Computer Science & Mathematics
http://www.mdpi.com/journal/computer-math
Latest open access articles published in Computer Science & Mathematics at http://www.mdpi.com/journal/computer-math<![CDATA[IJFS, Vol. 3, Pages 342-350: Determinants of the Government Bond Yield in Spain: A Loanable Funds Model]]>
http://www.mdpi.com/2227-7072/3/3/342
This paper applies demand and supply analysis to examine the government bond yield in Spain. The sample ranges from 1999.Q1 to 2014.Q2. The EGARCH model is employed in empirical work. The Spanish government bond yield is positively associated with the government debt/GDP ratio, the short-term Treasury bill rate, the expected inflation rate, the U.S. 10 year government bond yield and a dummy variable representing the debt crisis and negatively affected by the GDP growth rate and the expected nominal effective exchange rate.International Journal of Financial Studies2015-07-3033Article10.3390/ijfs30303423423502227-70722015-07-30doi: 10.3390/ijfs3030342Yu Hsing<![CDATA[IJGI, Vol. 4, Pages 1290-1300: Enhancing Disaster Management: Development of a Spatial Database of Day Care Centers in the USA]]>
http://www.mdpi.com/2220-9964/4/3/1290
Children under the age of five constitute around 7% of the total U.S. population, and represent a segment of the population that is totally dependent on others for day-to-day activities. A significant proportion of this population spends time in some form of day care arrangement while their parents are away from home. Accounting for those children during emergencies is of high priority, which requires a broad understanding of the locations of such day care centers. As concentrations of at risk population, the spatial location of day care centers is critical for any type of emergency preparedness and response (EPR). However, until recently, the U.S. emergency preparedness and response community did not have access to a comprehensive spatial database of day care centers at the national scale. This paper describes an approach for the development of the first comprehensive spatial database of day care center locations throughout the U.S. utilizing a variety of data harvesting techniques to integrate information from widely disparate data sources followed by geolocating for spatial precision. In the context of disaster management, such spatially refined demographic databases hold tremendous potential for improving high-resolution population distribution and dynamics models and databases.ISPRS International Journal of Geo-Information2015-07-3043Article10.3390/ijgi4031290129013002220-99642015-07-30doi: 10.3390/ijgi4031290Nagendra SinghMark TuttleBudhendra Bhaduri<![CDATA[Robotics, Vol. 4, Pages 284-315: Intent Understanding Using an Activation Spreading Architecture]]>
http://www.mdpi.com/2218-6581/4/3/284
In this paper, we propose a new approach for recognizing intentions of humans by observing their activities with a color plus depth (RGB-D) camera. Activities and goals are modeled as a distributed network of inter-connected nodes in an Activation Spreading Network (ASN). Inspired by a formalism in hierarchical task networks, the structure of the network captures the hierarchical relationship between high-level goals and low-level activities that realize these goals. Our approach can detect intentions before they are realized and it can work in real-time. We also extend the formalism of ASNs to incorporate contextual information into intent recognition. We further augment the ASN formalism with special nodes and synaptic connections to model ordering constraints between actions, in order to represent and handle partial-order plans in our ASN. A fully functioning system is developed for experimental evaluation. We implemented a robotic system that uses our intent recognition to naturally interact with the user. Our ASN based intent recognizer is tested against three different scenarios involving everyday activities performed by a subject, and our results show that the proposed approach is able to detect low-level activities and recognize high-level intentions effectively in real-time. Further analysis shows that contextual and partial-order ASNs are able to discriminate between otherwise ambiguous goals.Robotics2015-07-3043Article10.3390/robotics40302842843152218-65812015-07-30doi: 10.3390/robotics4030284Mohammad SaffarMircea NicolescuMonica NicolescuBanafsheh Rekabdar<![CDATA[Econometrics, Vol. 3, Pages 577-589: A Spectral Model of Turnover Reduction]]>
http://www.mdpi.com/2225-1146/3/3/577
We give a simple explicit formula for turnover reduction when a large number of alphas are traded on the same execution platform and trades are crossed internally. We model turnover reduction via alpha correlations. Then, for a large number of alphas, turnover reduction is related to the largest eigenvalue and the corresponding eigenvector of the alpha correlation matrix.Econometrics2015-07-2933Article10.3390/econometrics30305775775892225-11462015-07-29doi: 10.3390/econometrics3030577Zura Kakushadze<![CDATA[Electronics, Vol. 4, Pages 507-525: A FPGA-Based Broadband EIT System for Complex Bioimpedance Measurements—Design and Performance Estimation]]>
http://www.mdpi.com/2079-9292/4/3/507
Electrical impedance tomography (EIT) is an imaging method that is able to estimate the electrical conductivity distribution of living tissue. This work presents a field programmable gate array (FPGA)-based multi-frequency EIT system for complex, time-resolved bioimpedance measurements. The system has the capability to work with measurement setups with up to 16 current electrodes and 16 voltage electrodes. The excitation current has a range of about 10 µA to 5 mA, whereas the sinusoidal signal used for excitation can have a frequency of up to 500 kHz. Additionally, the usage of a chirp or rectangular signal excitation is possible. Furthermore, the described system has a sample rate of up to 3480 impedance spectra per second (ISPS). The performance of the EIT system is demonstrated with a resistor-based phantom and tank phantoms. Additionally, first measurements taken from the human thorax during a breathing cycle are presented.Electronics2015-07-2943Article10.3390/electronics40305075075252079-92922015-07-29doi: 10.3390/electronics4030507Roman KuscheAnkit MalhotraMartin RyschkaGunther ArdeltPaula KlimachSteffen Kaufmann<![CDATA[Algorithms, Vol. 8, Pages 552-561: Some Improvements to a Third Order Variant of Newton’s Method from Simpson’s Rule]]>
http://www.mdpi.com/1999-4893/8/3/552
In this paper, we present three improvements to a three-point third order variant of Newton’s method derived from the Simpson rule. The first one is a fifth order method using the same number of functional evaluations as the third order method, the second one is a four-point 10th order method and the last one is a five-point 20th order method. In terms of computational point of view, our methods require four evaluations (one function and three first derivatives) to get fifth order, five evaluations (two functions and three derivatives) to get 10th order and six evaluations (three functions and three derivatives) to get 20th order. Hence, these methods have efficiency indexes of 1.495, 1.585 and 1.648, respectively which are better than the efficiency index of 1.316 of the third order method. We test the methods through some numerical experiments which show that the 20th order method is very efficient.Algorithms2015-07-2983Article10.3390/a80305525525611999-48932015-07-29doi: 10.3390/a8030552Diyashvir Babajee<![CDATA[Algorithms, Vol. 8, Pages 541-551: Target Detection Algorithm Based on Two Layers Human Visual System]]>
http://www.mdpi.com/1999-4893/8/3/541
Robust small target detection of low signal-to-noise ratio (SNR) is very important in infrared search and track applications for self-defense or attacks. Due to the complex background, current algorithms have some unsolved issues with false alarm rate. In order to reduce the false alarm rate, an infrared small target detection algorithm based on saliency detection and support vector machine was proposed. Firstly, we detect salient regions that may contain targets with phase spectrum Fourier transform (PFT) approach. Then, target recognition was performed in the salient regions. Experimental results show the proposed algorithm has ideal robustness and efficiency for real infrared small target detection applications.Algorithms2015-07-2983Article10.3390/a80305415415511999-48932015-07-29doi: 10.3390/a8030541Zheng CuiJingli YangShouda JiangChangan Wei<![CDATA[IJGI, Vol. 4, Pages 1265-1289: Application of Geo-Information Techniques in Land Use and Land Cover Change Analysis in a Peri-Urban District of Ghana]]>
http://www.mdpi.com/2220-9964/4/3/1265
Using Satellite Remote Sensing and Geographic Information System, this paper analyzes the land use and land cover change dynamics in the Bosomtwe District of Ghana, for 1986, 2010 thematic mapper and enhanced thematic Mapper+ (TM/ETM+) images, and 2014 Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI/TIS) image. The three images were geo-referenced and processed for classification, using the maximum likelihood classifier algorithm. A Jeffries-Matusita’s separability check was used in confirming the degree of spectral separation acceptability of the bands used for each of the land use and land cover classes. The best Kappa hat statistic of classification accuracy was 83%. Land Use and Land Cover (LULC) transition analysis in Environmental Systems Research Institute ESRI’s ArcMap was performed. The results of the classification over the three periods showed that built up, bare land and concrete surfaces increased from 1201 in 1986 to 5454 ha in 2010. Dense forest decreased by 2253 ha over the same period and increased by 873 ha by the 2014. Low forest also decreased by 1043 ha in 2010; however, it increased by 13% in 2014. Our findings showed some of the important changes in the land use and land cover patterns in the District. After the urbanization process, coupled with farmland abandonment, between 1986 and 2010, substantial increments in urban land and clear increments in farmland coverage between 1986 and 2014were found to be the reason for vegetation cover decreases. This suggests that major changes in the socio-ecological driving forces affecting landscape dynamics have occurred in the last few decades.ISPRS International Journal of Geo-Information2015-07-2843Article10.3390/ijgi4031265126512892220-99642015-07-28doi: 10.3390/ijgi4031265Divine AppiahDietrich SchröderEric ForkuoJohn Bugri<![CDATA[Information, Vol. 6, Pages 432-442: Sliding-Mode Speed Control of PMSM with Fuzzy-Logic Chattering Minimization—Design and Implementation]]>
http://www.mdpi.com/2078-2489/6/3/432
In this paper a Sliding Mode Control scheme (SMC) applied to the Permanent Magnet Synchronous Motor (PMSM) speed control is designed and improved. A Fuzzy logic algorithm is added to mitigate chattering caused by discontinuous term in steady states, and to ensure good performances of the controller in transient states. The proposed Fuzzy-SMC performance is tested in simulation and experimental results are obtained using eZdsp F28335.Information2015-07-2863Article10.3390/info60304324324422078-24892015-07-28doi: 10.3390/info6030432Fadil HichamDriss YousfiAite YounessElhafyani LarbiNasrudin Rahim<![CDATA[Mathematics, Vol. 3, Pages 653-665: Zeta Function Expression of Spin Partition Functions on Thermal AdS3]]>
http://www.mdpi.com/2227-7390/3/3/653
We find a Selberg zeta function expression of certain one-loop spin partition functions on three-dimensional thermal anti-de Sitter space. Of particular interest is the partition function of higher spin fermionic particles. We also set up, in the presence of spin, a Patterson-type formula involving the logarithmic derivative of zeta.Mathematics2015-07-2833Article10.3390/math30306536536652227-73902015-07-28doi: 10.3390/math3030653Floyd L.Williams<![CDATA[Computers, Vol. 4, Pages 234-250: An Investigation of Turkish Pre-Service Teachers’ Technological, Pedagogical and Content Knowledge]]>
http://www.mdpi.com/2073-431X/4/3/234
The purpose of this study is to investigate pre-service teachers’ technological, pedagogical and content knowledge (TPACK) in Turkey. By using the “Survey of Pre-service Teachers’ Knowledge of Teaching and Technology” developed by Schmidt et al. (2009), the study sought to determine if significant differences could be found in pre-service teachers’ perceptions of TPACK when examined by gender, age, educational program, year of study, kind of instruction (day or night education) and field experience. Regression analysis was also used to examine if technology knowledge (TK), pedagogical knowledge (PK) and content knowledge (CK) significantly contributed to pre-service teachers’ TPACK development. Participants of this study were 491 elementary pre-service teachers who attended the summer semester at Pamukkale University. The analysis of the collected data found a significant difference in pre-service teachers’ perceptions of the TPACK when examined across gender, program, year of study and field experience, but no significant differences were found regarding age and kind of instruction. Finally, our regression model showed that CK and PK contributed significantly to pre-service teachers’ TPACK development, but TK was not a significant predictor.Computers2015-07-2743Article10.3390/computers40302342342502073-431X2015-07-27doi: 10.3390/computers4030234Duygu Cetin-BerberAli Erdem<![CDATA[Information, Vol. 6, Pages 411-431: On Semantic Information in Nature]]>
http://www.mdpi.com/2078-2489/6/3/411
The connection between semantic information and evolution has gained growing attention recently. Evolution in this contribution—as in others before—we consider as being driven by information. Semantic information, as we consider it, is based on energy. It follows syntactic and semantic rules. We assume syntax, semantics and pragmatics to be structural features of information in biological evolution. These features started to evolve with the very beginning of life and have become more complex and richer in the course of the unfolding biological evolution across all species. We argue that semantic information is an exclusive feature of biological evolution. We present an information model covering this which to a certain degree—it does not cover quantitative aspects—complements Shannon’s information theory and opens novel views on informational based processes in nature.Information2015-07-2763Article10.3390/info60304114114312078-24892015-07-27doi: 10.3390/info6030411Wolfgang Johannsen<![CDATA[IJGI, Vol. 4, Pages 1246-1264: A Progressive Buffering Method for Road Map Update Using OpenStreetMap Data]]>
http://www.mdpi.com/2220-9964/4/3/1246
Web 2.0 enables a two-way interaction between servers and clients. GPS receivers become available to more citizens and are commonly found in vehicles and smart phones, enabling individuals to record and share their trajectory data on the Internet and edit them online. OpenStreetMap (OSM) makes it possible for citizens to contribute to the acquisition of geographic information. This paper studies the use of OSM data to find newly mapped or built roads that do not exist in a reference road map and create its updated version. For this purpose, we propose a progressive buffering method for determining an optimal buffer radius to detect the new roads in the OSM data. In the next step, the detected new roads are merged into the reference road maps geometrically, topologically, and semantically. Experiments with OSM data and reference road maps over an area of 8494 km2 in the city of Wuhan, China and five of its 5 km × 5 km areas are conducted to demonstrate the feasibility and effectiveness of the method. It is shown that the OSM data can add 11.96% or a total of 2008.6 km of new roads to the reference road maps with an average precision of 96.49% and an average recall of 97.63%.ISPRS International Journal of Geo-Information2015-07-2743Article10.3390/ijgi4031246124612642220-99642015-07-27doi: 10.3390/ijgi4031246Changyong LiuLian XiongXiangyun HuJie Shan<![CDATA[Axioms, Vol. 4, Pages 313-320: Fixed Points of Local Actions of Lie Groups on Real and Complex 2-Manifolds]]>
http://www.mdpi.com/2075-1680/4/3/313
I discuss old and new results on fixed points of local actions by Lie groups G on real and complex 2-manifolds, and zero sets of Lie algebras of vector fields. Results of E. Lima, J. Plante and C. Bonatti are reviewed.Axioms2015-07-2743Article10.3390/axioms40303133133202075-16802015-07-27doi: 10.3390/axioms4030313Morris Hirsch<![CDATA[Algorithms, Vol. 8, Pages 529-540: A Parallel Search Strategy Based on Sparse Representation for Infrared Target Tracking]]>
http://www.mdpi.com/1999-4893/8/3/529
A parallel search strategy based on sparse representation (PS-L1 tracker) is proposed in the particle filter framework. To obtain the weights of state particles, target templates are represented linearly with the dictionary of target candidates. Sparse constraints on the coefficient guarantee that only true target candidates can be selected, and the nonnegative entries denote the associate weights of efficient target states. Then the optimal target state can be estimated by the linear combination of above weighted states. In this way, efficient target states are selected simultaneously from all the particles, which we call a parallel search strategy. Experimental results demonstrate excellent performance of the proposed method on challenging infrared images.Algorithms2015-07-2783Article10.3390/a80305295295401999-48932015-07-27doi: 10.3390/a8030529Zhen ShiChang'an WeiPing FuShouda Jiang<![CDATA[IJFS, Vol. 3, Pages 319-341: Forecasting Returns with Fundamentals-Removed Investor Sentiment]]>
http://www.mdpi.com/2227-7072/3/3/319
The Baker and Wurgler (2006) sentiment index purports to measure irrational investor sentiment, while the University of Michigan Consumer Sentiment Index is designed to largely reflect fundamentals. Removing this fundamental component from the Baker and Wurgler index creates an index of investor sentiment that may better capture irrational sentiment. This new index predicts returns better than the original Baker and Wurgler index as well as the alternative Baker and Wurgler sentiment index.International Journal of Financial Studies2015-07-2733Article10.3390/ijfs30303193193412227-70722015-07-27doi: 10.3390/ijfs3030319Adam Stivers<![CDATA[IJFS, Vol. 3, Pages 280-318: Large-Scale Empirical Tests of the Markov Tree Model]]>
http://www.mdpi.com/2227-7072/3/3/280
The Markov Tree model is a discrete-time option pricing model that accounts for short-term memory of the underlying asset. In this work, we compare the empirical performance of the Markov Tree model against that of the Black-Scholes model and Heston’s stochastic volatility model. Leveraging a total of five years of individual equity and index option data, and using three new methods for fitting the Markov Tree model, we find that the Markov Tree model makes smaller out-of-sample hedging errors than competing models. This comparison includes versions of Markov Tree and Black-Scholes models in which volatilities are strike- and maturity-dependent. Visualizing the errors over time, we find that the Markov Tree model yields more accurate and less risky single instrument hedges than Heston’s stochastic volatility model. A statistical resampling method indicates that the Markov Tree model’s superior hedging performance is due to its robustness with respect to noise in option data.International Journal of Financial Studies2015-07-2733Article10.3390/ijfs30302802803182227-70722015-07-27doi: 10.3390/ijfs3030280Harish BhatNitesh Kumar<![CDATA[Computers, Vol. 4, Pages 215-233: Security Property Validation of the Sensor Network Encryption Protocol (SNEP)]]>
http://www.mdpi.com/2073-431X/4/3/215
Since wireless sensor networks (WSNs) have been designed to be deployed in an unsecured, public environment, secured communication is really vital for their wide-spread use. Among all of the communication protocols developed for WSN, the Security Protocols for Sensor Networks (SPINS) is exceptional, as it has been designed with security as a goal. SPINS is composed of two building blocks: Secure Network Encryption Protocol (SNEP) and the “micro” version of the Timed Efficient Streaming Loss-tolerant Authentication (TESLA), named μTESLA. From the inception of SPINS, a number of efforts have been made to validate its security properties. In this paper, we have validated the security properties of SNEP by using an automated security protocol validation tool, named AVISPA. Using the protocol specification language, HLPSL, we model two combined scenarios—node to node key agreement and counter exchange protocols—followed by data transmission. Next, we validate the security properties of these combined protocols, using different AVISPA back-ends. AVISPA reports the models we have developed free from attacks. However, by analyzing the key distribution sub-protocol, we find one threat of a potential DoS attack that we have demonstrated by modeling in AVISPA. Finally, we propose a modification, and AVISPA reports this modified version free from the potential DoS attack.Computers2015-07-2443Article10.3390/computers40302152152332073-431X2015-07-24doi: 10.3390/computers4030215Salekul Islam<![CDATA[Axioms, Vol. 4, Pages 294-312: Pro-Lie Groups: A Survey with Open Problems]]>
http://www.mdpi.com/2075-1680/4/3/294
A topological group is called a pro-Lie group if it is isomorphic to a closed subgroup of a product of finite-dimensional real Lie groups. This class of groups is closed under the formation of arbitrary products and closed subgroups and forms a complete category. It includes each finite-dimensional Lie group, each locally-compact group that has a compact quotient group modulo its identity component and, thus, in particular, each compact and each connected locally-compact group; it also includes all locally-compact Abelian groups. This paper provides an overview of the structure theory and the Lie theory of pro-Lie groups, including results more recent than those in the authors’ reference book on pro-Lie groups. Significantly, it also includes a review of the recent insight that weakly-complete unital algebras provide a natural habitat for both pro-Lie algebras and pro-Lie groups, indeed for the exponential function that links the two. (A topological vector space is weakly complete if it is isomorphic to a power RX of an arbitrary set of copies of R. This class of real vector spaces is at the basis of the Lie theory of pro-Lie groups.) The article also lists 12 open questions connected to pro-Lie groups.Axioms2015-07-2443Article10.3390/axioms40302942943122075-16802015-07-24doi: 10.3390/axioms4030294Karl HofmannSidney Morris<![CDATA[Future Internet, Vol. 7, Pages 257-275: Vehicular Internet: Security & Privacy Challenges and Opportunities]]>
http://www.mdpi.com/1999-5903/7/3/257
The vehicular internet will drive the future of vehicular technology and intelligent transportation systems (ITS). Whether it is road safety, infotainment, or driver-less cars, the vehicular internet will lay the foundation for the future of road travel. Governments and companies are pursuing driver-less vehicles as they are considered to be more reliable than humans and, therefore, safer. The vehicles today are not just a means of transportation but are also equipped with a wide range of sensors that provide valuable data. If vehicles are enabled to share data that they collect with other vehicles or authorities for decision-making and safer driving, they thereby form a vehicular network. However, there is a lot at stake in vehicular networks if they are compromised. With the stakes so high, it is imperative that the vehicular networks are secured and made resilient to any attack or attempt that may have serious consequences. The vehicular internet can also be the target of a cyber attack, which can be devastating. In this paper, the opportunities that the vehicular internet offers are presented and then various security and privacy aspects are discussed and some solutions are presented.Future Internet2015-07-2473Article10.3390/fi70302572572751999-59032015-07-24doi: 10.3390/fi7030257Kamran ZaidiMuttukrishnan Rajarajan<![CDATA[Electronics, Vol. 4, Pages 480-506: Flexible Electronics: Integration Processes for Organic and Inorganic Semiconductor-Based Thin-Film Transistors]]>
http://www.mdpi.com/2079-9292/4/3/480
Flexible and transparent electronics have been studied intensively during the last few decades. The technique establishes the possibility of fabricating innovative products, from flexible displays to radio-frequency identification tags. Typically, large-area polymeric substrates such as polypropylene (PP) or polyethylene terephthalate (PET) are used, which produces new requirements for the integration processes. A key element for flexible and transparent electronics is the thin-film transistor (TFT), as it is responsible for the driving current in memory cells, digital circuits or organic light-emitting devices (OLEDs). In this paper, we discuss some fundamental concepts of TFT technology. Additionally, we present a comparison between the use of the semiconducting organic small-molecule pentacene and inorganic nanoparticle semiconductors in order to integrate TFTs suitable for flexible electronics. Moreover, a technique for integration with a submicron resolution suitable for glass and foil substrates is presented.Electronics2015-07-2443Review10.3390/electronics40304804805062079-92922015-07-24doi: 10.3390/electronics4030480Fábio VidorThorsten MeyersUlrich Hilleringmann<![CDATA[Risks, Vol. 3, Pages 290-317: Life Insurance Cash Flows with Policyholder Behavior]]>
http://www.mdpi.com/2227-9091/3/3/290
The problem of the valuation of life insurance payments with policyholder behavior is studied. First, a simple survival model is considered, and it is shown how cash flows without policyholder behavior can be modified to include surrender and free policy behavior by calculation of simple integrals. In the second part, a more general disability model with recovery is studied. Here, cash flows are determined by solving a modified Kolmogorov forward differential equation. We conclude the paper with numerical examples illustrating the methods proposed and the impact of policyholder behavior.Risks2015-07-2433Article10.3390/risks30302902903172227-90912015-07-24doi: 10.3390/risks3030290Kristian BuchardtThomas Møller<![CDATA[Risks, Vol. 3, Pages 277-289: Monopolistic Insurance and the Value of Information]]>
http://www.mdpi.com/2227-9091/3/3/277
The value of information regarding risk class for a monopoly insurer and its customers is examined in both symmetric and asymmetric information environments. A monopolist always prefers contracting with uninformed customers as this maximizes the rent extracted under symmetric information while also avoiding the cost of adverse selection when information is held asymmetrically. Although customers are indifferent to symmetric information when they are initially uninformed, they prefer contracting with hidden knowledge rather than symmetric information since the monopoly responds to adverse selection by sharing gains from trade with high-risk customers when low risks are predominant in the insurance pool. However, utilitarian social welfare is highest when customers are uninformed, and is higher when information is symmetric rather than asymmetric.Risks2015-07-2433Article10.3390/risks30302772772892227-90912015-07-24doi: 10.3390/risks3030277Arthur Snow<![CDATA[IJFS, Vol. 3, Pages 244-279: Systemic Risk in the European Union: A Network Approach to Banks’ Sovereign Debt Exposures]]>
http://www.mdpi.com/2227-7072/3/3/244
This paper draws on network theory to investigate European banks’ sovereign debt exposures. Banks’ holdings of sovereign debt build a network of financial linkages with European countries that exhibits a long-tail distribution of node degrees. A highly connected network core of 15 banks is identified. These banks accounted for the majority of sovereign debt investments between December 2010 and December 2013 but exhibited only average and sometimes even below average capitalizations. Consequently, they constituted a potential source and transmission channel of systemic risk, especially due to their proneness to portfolio contagion. In a complementary regression analysis, the effect of counterparty risk on Credit Default Swap (CDS) spreads of 15 EU sovereigns is investigated. Among the banks exposed to the debt of a particular issuer, the biggest institutions in terms of their own asset sizes are identified and some of their balance sheet characteristics included into the regression. The analysis finds that the banks’ implied volatilities had a significant and increasing effect on CDS spreads during the recent crisis years, providing evidence of the presence of counterparty risk and its effect on EU sovereign debt pricing. Furthermore, the role of the domestic financial sectors is assessed and found to have affected the CDS spreads.International Journal of Financial Studies2015-07-2333Article10.3390/ijfs30302442442792227-70722015-07-23doi: 10.3390/ijfs3030244Annika Westphal<![CDATA[JSAN, Vol. 4, Pages 160-188: Context-Aware Local Optimization of Sensor Network Deployment]]>
http://www.mdpi.com/2224-2708/4/3/160
Wireless sensor networks are increasingly used for tracking and monitoring dynamic phenomena in urban and natural areas. Spatial coverage is an important issue in sensor networks in order to fulfill the needs of sensing applications. Optimization methods are widely used to efficiently distribute sensor nodes in the network to achieve a desired level of coverage. Most of the existing algorithms do not consider the characteristics of the real environment in the optimization process. In this paper, we propose the integration of contextual information in optimization algorithms to improve sensor network coverage. First, we investigate the implication of contextual information in sensor networks. Then, a conceptual framework for local context-aware sensor network deployment optimization method is introduced and related algorithms are presented in detail. Finally, several experiments are carried out to evaluate the validity of the proposed method. The results obtained from these experiments show the effectiveness of our approach in different contextual situations.Journal of Sensor and Actuator Networks2015-07-2343Article10.3390/jsan40301601601882224-27082015-07-23doi: 10.3390/jsan4030160Meysam ArganyMir MostafaviChristian Gagné<![CDATA[Electronics, Vol. 4, Pages 424-479: Review on Physically Flexible Nonvolatile Memory for Internet of Everything Electronics]]>
http://www.mdpi.com/2079-9292/4/3/424
Solid-state memory is an essential component of the digital age. With advancements in healthcare technology and the Internet of Things (IoT), the demand for ultra-dense, ultra-low-power memory is increasing. In this review, we present a comprehensive perspective on the most notable approaches to the fabrication of physically flexible memory devices. With the future goal of replacing traditional mechanical hard disks with solid-state storage devices, a fully flexible electronic system will need two basic devices: transistors and nonvolatile memory. Transistors are used for logic operations and gating memory arrays, while nonvolatile memory (NVM) devices are required for storing information in the main memory and cache storage. Since the highest density of transistors and storage structures is manifested in memories, the focus of this review is flexible NVM. Flexible NVM components are discussed in terms of their functionality, performance metrics, and reliability aspects, all of which are critical components for NVM technology to be part of mainstream consumer electronics, IoT, and advanced healthcare devices. Finally, flexible NVMs are benchmarked and future prospects are provided.Electronics2015-07-2343Review10.3390/electronics40304244244792079-92922015-07-23doi: 10.3390/electronics4030424Mohamed GhoneimMuhammad Hussain<![CDATA[Algorithms, Vol. 8, Pages 514-528: On the Accessibility of Newton’s Method under a Hölder Condition on the First Derivative]]>
http://www.mdpi.com/1999-4893/8/3/514
We see how we can improve the accessibility of Newton’s method for approximating a solution of a nonlinear equation in Banach spaces when a center Hölder condition on the first derivative is used to prove its semi-local convergence.Algorithms2015-07-2383Article10.3390/a80305145145281999-48932015-07-23doi: 10.3390/a8030514José EzquerroMiguel Hernández-Verón<![CDATA[IJFS, Vol. 3, Pages 230-243: Bond Indenture Consent Solicitations as a Debt Management Tool]]>
http://www.mdpi.com/2227-7072/3/3/230
Many companies in recent years are seeking new ways to manage their debt liabilities. Companies with outstanding debt securities can engage in a variety of transactions with bond holders. Choices will depend to some extent on whether or not the company has access to cash and is able to purchase in the open market or through cash tender offer, or if without cash, by making an exchange offer of new securities for existing securities. Often in either case, there is a bond indenture consent solicitation needed to waive or amend existing bond terms, the announcement of which signals management’s intent to the market. Given the increasing prevalence of this practice as a debt management tool, this study seeks to determine whether it is truly perceived to be value enhancing by stockholders. Using an event study of 50 companies announcing bond indenture consent solicitations, we find that shareholders do benefit, and companies appear well served by this practice.International Journal of Financial Studies2015-07-2233Article10.3390/ijfs30302302302432227-70722015-07-22doi: 10.3390/ijfs3030230Jamie Anderson-ParsonTerrill KeaslerRobin Byerly<![CDATA[IJGI, Vol. 4, Pages 1225-1245: MAARGHA: A Prototype System for Road Condition and Surface Type Estimation by Fusing Multi-Sensor Data]]>
http://www.mdpi.com/2220-9964/4/3/1225
Road infrastructure in countries like India is expanding at a rapid pace and is becoming increasingly difficult for authorities to identify and fix the bad roads in time. Current Geographical Information Systems (GIS) lack information about on-road features like road surface type, speed breakers and dynamic attribute data like the road quality. Hence there is a need to build road monitoring systems capable of collecting such information periodically. Limitations of satellite imagery with respect to the resolution and availability, makes road monitoring primarily an on-field activity. Monitoring is currently performed using special vehicles that are fitted with expensive laser scanners and need skilled resource besides providing only very low coverage. Hence such systems are not suitable for continuous road monitoring. Cheaper alternative systems using sensors like accelerometer and GPS (Global Positioning System) exists but they are not equipped to achieve higher information levels. This paper presents a prototype system MAARGHA (MAARGHA in Sanskrit language means an eternal path to solution), which demonstrates that it can overcome the disadvantages of the existing systems by fusing multi-sensory data like camera image, accelerometer data and GPS trajectory at an information level, apart from providing additional road information like road surface type. MAARGHA has been tested across different road conditions and sensor data characteristics to assess its potential applications in real world scenarios. The developed system achieves higher information levels when compared to state of the art road condition estimation systems like Roadroid. The system performance in road surface type classification is dependent on the local environmental conditions at the time of imaging. In our study, the road surface type classification accuracy reached 100% for datasets with near ideal environmental conditions and dropped down to 60% for datasets with shadows and obstacles.ISPRS International Journal of Geo-Information2015-07-2243Article10.3390/ijgi4031225122512452220-99642015-07-22doi: 10.3390/ijgi4031225Deepak RajamohanBhavana GannuKrishnan Rajan<![CDATA[Econometrics, Vol. 3, Pages 561-576: A Note on the Asymptotic Normality of the Kernel Deconvolution Density Estimator with Logarithmic Chi-Square Noise]]>
http://www.mdpi.com/2225-1146/3/3/561
This paper studies the asymptotic normality for the kernel deconvolution estimator when the noise distribution is logarithmic chi-square; both identical and independently distributed observations and strong mixing observations are considered. The dependent case of the result is applied to obtain the pointwise asymptotic distribution of the deconvolution volatility density estimator in discrete-time stochastic volatility models.Econometrics2015-07-2133Short Note10.3390/econometrics30305615615762225-11462015-07-21doi: 10.3390/econometrics3030561Yang Zu<![CDATA[Mathematics, Vol. 3, Pages 644-652: On the Nature of the Tsallis–Fourier Transform]]>
http://www.mdpi.com/2227-7390/3/3/644
By recourse to tempered ultradistributions, we show here that the effect of a q-Fourier transform (qFT) is to map equivalence classes of functions into other classes in a one-to-one fashion. This suggests that Tsallis’ q-statistics may revolve around equivalence classes of distributions and not individual ones, as orthodox statistics does. We solve here the qFT’s non-invertibility issue, but discover a problem that remains open.Mathematics2015-07-2133Article10.3390/math30306446446522227-73902015-07-21doi: 10.3390/math3030644A. PlastinoMario Rocca<![CDATA[Information, Vol. 6, Pages 399-410: Multi-Criteria Vertical Handover Comparison between Wimax and Wifi]]>
http://www.mdpi.com/2078-2489/6/3/399
In next generation wireless networks, the most tempting feature is the ability of the user to move smoothly over different access networks regardless of the network access technology. In this paper we study the benefit of Multiple Attribute Decision Making (MADM) strategies for network selection. We compare three of these methods naming Simple Additive Weighting (SAW), Multiplicative Exponential Weighting (MEW) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) in a realtime ns-3 simulation. Analytic Hierarchy Process (AHP) provides the weights of attributes which allow the comparison in different types of applications. Therefore, we propose a performance evaluation model with a reconfiguration of AHP parameters used in the literature. Simulation results show that the proposed parameters provide an improvement of Delay and offer allowable Packet loss in different types of applications.Information2015-07-2163Article10.3390/info60303993994102078-24892015-07-21doi: 10.3390/info6030399Maroua DrissiMohammed Oumsis<![CDATA[Axioms, Vol. 4, Pages 275-293: Heat Kernel Embeddings, Differential Geometry and Graph Structure]]>
http://www.mdpi.com/2075-1680/4/3/275
In this paper, we investigate the heat kernel embedding as a route to graph representation. The heat kernel of the graph encapsulates information concerning the distribution of path lengths and, hence, node affinities on the graph; and is found by exponentiating the Laplacian eigen-system over time. A Young–Householder decomposition is performed on the heat kernel to obtain the matrix of the embedded coordinates for the nodes of the graph. With the embeddings at hand, we establish a graph characterization based on differential geometry by computing sets of curvatures associated with the graph edges and triangular faces. A sectional curvature computed from the difference between geodesic and Euclidean distances between nodes is associated with the edges of the graph. Furthermore, we use the Gauss–Bonnet theorem to compute the Gaussian curvatures associated with triangular faces of the graph.Axioms2015-07-2143Article10.3390/axioms40302752752932075-16802015-07-21doi: 10.3390/axioms4030275Hewayda ElGhawalbyEdwin Hancock<![CDATA[Economies, Vol. 3, Pages 128-146: Inflation and Inflation Uncertainty Revisited: Evidence from Egypt]]>
http://www.mdpi.com/2227-7099/3/3/128
The welfare costs of inflation and inflation uncertainty are well documented in the literature and empirical evidence on the link between the two is sparse in the case of Egypt. This paper investigates the causal relationship between inflation and inflation uncertainty in Egypt using monthly time series data during the period January 1974–April 2015. To endogenously control for any potential structural breaks in the inflation time series, Zivot and Andrews (2002) and Clemente–Montanes–Reyes (1998) unit root tests are used. The inflation–inflation uncertainty relation is modeled by the standard two-step approach as well as simultaneously using various versions of the GARCH-M model to control for any potential feedback effects. The analyses explicitly control for the effect of the Economic Reform and Structural Adjustment Program (ERSAP) undertaken by the Egyptian government in the early 1990s, which affected inflation rate and its associated volatility. Results show a high degree of inflation–volatility persistence in the response to inflationary shocks. Granger-causality test along with symmetric and asymmetric GARCH-M models indicate a statistically significant bi-directional positive relationship between inflation and inflation uncertainty, supporting both the Friedman–Ball and the Cukierman–Meltzer hypotheses. The findings are robust to the various estimation methods and model specifications. The findings of this paper support the view of adopting inflation-targeting policy in Egypt, after fulfilling its preconditions, to reduce the welfare cost of inflation and its related uncertainties. Monetary authorities in Egypt should enhance the credibility of monetary policy and attempt to reduce inflation uncertainty, which will help lower inflation rates.Economies2015-07-2033Article10.3390/economies30301281281462227-70992015-07-20doi: 10.3390/economies3030128Mesbah Sharaf<![CDATA[Axioms, Vol. 4, Pages 268-274: Closed-Form Representations of the Density Function and Integer Moments of the Sample Correlation Coefficient]]>
http://www.mdpi.com/2075-1680/4/3/268
This paper provides a simplified representation of the exact density function of R, the sample correlation coefficient. The odd and even moments of R are also obtained in closed forms. Being expressed in terms of generalized hypergeometric functions, the resulting representations are readily computable. Some numerical examples corroborate the validity of the results derived herein.Axioms2015-07-2043Article10.3390/axioms40302682682742075-16802015-07-20doi: 10.3390/axioms4030268Serge Provost<![CDATA[Symmetry, Vol. 7, Pages 1333-1351: A Framework for Symmetric Part Detection in Cluttered Scenes]]>
http://www.mdpi.com/2073-8994/7/3/1333
The role of symmetry in computer vision has waxed and waned in importance during the evolution of the field from its earliest days. At first figuring prominently in support of bottom-up indexing, it fell out of favour as shape gave way to appearance and recognition gave way to detection. With a strong prior in the form of a target object, the role of the weaker priors offered by perceptual grouping was greatly diminished. However, as the field returns to the problem of recognition from a large database, the bottom-up recovery of the parts that make up the objects in a cluttered scene is critical for their recognition. The medial axis community has long exploited the ubiquitous regularity of symmetry as a basis for the decomposition of a closed contour into medial parts. However, today’s recognition systems are faced with cluttered scenes and the assumption that a closed contour exists, i.e., that figure-ground segmentation has been solved, rendering much of the medial axis community’s work inapplicable. In this article, we review a computational framework, previously reported in [1–3], that bridges the representation power of the medial axis and the need to recover and group an object’s parts in a cluttered scene. Our framework is rooted in the idea that a maximally-inscribed disc, the building block of a medial axis, can be modelled as a compact superpixel in the image. We evaluate the method on images of cluttered scenes.Symmetry2015-07-2073Review10.3390/sym7031333133313512073-89942015-07-20doi: 10.3390/sym7031333Tom LeeSanja FidlerAlex LevinshteinCristian SminchisescuSven Dickinson<![CDATA[Symmetry, Vol. 7, Pages 1289-1332: Computing with Colored Tangles]]>
http://www.mdpi.com/2073-8994/7/3/1289
We suggest a diagrammatic model of computation based on an axiom of distributivity. A diagram of a decorated colored tangle, similar to those that appear in low dimensional topology, plays the role of a circuit diagram. Equivalent diagrams represent bisimilar computations. We prove that our model of computation is Turing complete and with bounded resources that it can decide any language in complexity class IP, sometimes with better performance parameters than corresponding classical protocols.Symmetry2015-07-2073Article10.3390/sym7031289128913322073-89942015-07-20doi: 10.3390/sym7031289Avishy CarmiDaniel Moskovich<![CDATA[IJFS, Vol. 3, Pages 194-229: Corporate Governance Provisions, Family Involvement, and Firm Performance in Publicly Traded Family Firms]]>
http://www.mdpi.com/2227-7072/3/3/194
This study examines the moderation effects of corporate governance provisions on the link between family involvement (i.e., family ownership and family management) in publicly-traded firms and firm performance by drawing upon agency theory, with a focus on principal-principal agency issues, and the extant family governance literature. We develop and test the hypotheses on 386 of the S&amp;P 500 firms longitudinally. Findings support the hypotheses suggesting the moderation effects of the use of provisions (a) protecting controlling owners in terms of their sustainability of controlling status, and (b) protecting management legally on the inverted U-shaped relationship between family ownership and firm performance. We also found support for the moderation effects of provisions (c) protecting controlling owners in terms of their voting rights, (d) protecting noncontrolling owners, and (e) protecting management monetarily on the inverted U-shaped relationship between family management and firm performance. By this, our study provides empirical support for the principal-principal agency perspective on the corporate governance in publicly-traded family firms. As such, it suggests new avenues of research for both the corporate governance literature, as well as for the theory of the family firm. Our study also offers insights to policy directed toward monitoring the actions of large shareholders such as family and enhancing the overall shareholder value in publicly-traded family firms.International Journal of Financial Studies2015-07-1733Article10.3390/ijfs30301941942292227-70722015-07-17doi: 10.3390/ijfs3030194Esra MemiliKaustav Misra<![CDATA[Information, Vol. 6, Pages 388-398: A Neural Network-Based Interval Pattern Matcher]]>
http://www.mdpi.com/2078-2489/6/3/388
One of the most important roles in the machine learning area is to classify, and neural networks are very important classifiers. However, traditional neural networks cannot identify intervals, let alone classify them. To improve their identification ability, we propose a neural network-based interval matcher in our paper. After summarizing the theoretical construction of the model, we take a simple and a practical weather forecasting experiment, which show that the recognizer accuracy reaches 100% and that is promising.Information2015-07-1763Article10.3390/info60303883883982078-24892015-07-17doi: 10.3390/info6030388Jing LuShengjun XueXiakun ZhangYang Han<![CDATA[Information, Vol. 6, Pages 375-387: Controlled Remote State Preparation via General Pure Three-Qubit State]]>
http://www.mdpi.com/2078-2489/6/3/375
The protocols for controlled remote state preparation of a single qubit and a general two-qubit state are presented in this paper. The general pure three-qubit states are chosen as shared quantum channel, which are not Local operations and classical communication (LOCC) equivalent to the mostly used GHz state. This is the first time that general pure three-qubit states have been introduced to complete remote state preparation. The probability of successful preparation is presented. Moreover, in some special cases, the successful probability could reach a unit value.Information2015-07-1763Article10.3390/info60303753753872078-24892015-07-17doi: 10.3390/info6030375Yuebo ZhaZhihua ZhangYulin HuangJianyu Yang<![CDATA[Information, Vol. 6, Pages 361-374: A Class of New Metrics Based on Triangular Discrimination]]>
http://www.mdpi.com/2078-2489/6/3/361
In the field of information theory, statistics and other application areas, the information-theoretic divergences are used widely. To meet the requirement of metric properties, we introduce a class of new metrics based on triangular discrimination which are bounded. Moreover, we obtain some sharp inequalities for the triangular discrimination and other information-theoretic divergences. Their asymptotic approximation properties are also involved.Information2015-07-1763Article10.3390/info60303613613742078-24892015-07-17doi: 10.3390/info6030361Guoxiang LuBingqing Li<![CDATA[Mathematics, Vol. 3, Pages 626-643: Time Automorphisms on C-Algebras]]>
http://www.mdpi.com/2227-7390/3/3/626
Applications of fractional time derivatives in physics and engineering require the existence of nontranslational time automorphisms on the appropriate algebra of observables. The existence of time automorphisms on commutative and noncommutative C*-algebras for interacting many-body systems is investigated in this article. A mathematical framework is given to discuss local stationarity in time and the global existence of fractional and nonfractional time automorphisms. The results challenge the concept of time flow as a translation along the orbits and support a more general concept of time flow as a convolution along orbits. Implications for the distinction of reversible and irreversible dynamics are discussed. The generalized concept of time as a convolution reduces to the traditional concept of time translation in a special limit.Mathematics2015-07-1633Article10.3390/math30306266266432227-73902015-07-16doi: 10.3390/math3030626R. Hilfer<![CDATA[Informatics, Vol. 2, Pages 20-30: MaPSeq, A Service-Oriented Architecture for Genomics Research within an Academic Biomedical Research Institution]]>
http://www.mdpi.com/2227-9709/2/3/20
Genomics research presents technical, computational, and analytical challenges that are well recognized. Less recognized are the complex sociological, psychological, cultural, and political challenges that arise when genomics research takes place within a large, decentralized academic institution. In this paper, we describe a Service-Oriented Architecture (SOA)—MaPSeq—that was conceptualized and designed to meet the diverse and evolving computational workflow needs of genomics researchers at our large, hospital-affiliated, academic research institution. We present the institutional challenges that motivated the design of MaPSeq before describing the architecture and functionality of MaPSeq. We then discuss SOA solutions and conclude that approaches such as MaPSeq enable efficient and effective computational workflow execution for genomics research and for any type of academic biomedical research that requires complex, computationally-intense workflows.Informatics2015-07-1623Article10.3390/informatics203002020302227-97092015-07-16doi: 10.3390/informatics2030020Jason ReillyStanley AhaltJohn McGeePhillips OwenCharles SchmittKirk Wilhelmsen<![CDATA[Risks, Vol. 3, Pages 250-276: Best-Estimates in Bond Markets with Reinvestment Risk]]>
http://www.mdpi.com/2227-9091/3/3/250
The concept of best-estimate, prescribed by regulators to value insurance liabilities for accounting and solvency purposes, has recently been discussed extensively in the industry and related academic literature. To differentiate hedgeable and non-hedgeable risks in a general case, recent literature defines best-estimates using orthogonal projections of a claim on the space of replicable payoffs. In this paper, we apply this concept of best-estimate to long-maturity claims in a market with reinvestment risk, since in this case the total liability cannot easily be separated into hedgeable and non-hedgeable parts. We assume that a limited number of short-maturity bonds are traded, and derive the best-estimate price of bonds with longer maturities, thus obtaining a best-estimate yield curve. We therefore use the multifactor Vasiˇcek model and derive within this framework closed-form expressions for the best-estimate prices of long-term bonds.Risks2015-07-1633Article10.3390/risks30302502502762227-90912015-07-16doi: 10.3390/risks3030250Anne MacKayMario Wüthrich<![CDATA[Symmetry, Vol. 7, Pages 1275-1288: Development of Network Analysis and Visualization System for KEGG Pathways]]>
http://www.mdpi.com/2073-8994/7/3/1275
Big data refers to informationalization technology for extracting valuable information through the use and analysis of large-scale data and, based on that data, deriving plans for response or predicting changes. With the development of software and devices for next generation sequencing, a vast amount of bioinformatics data has been generated recently. Also, bioinformatics data based big-data technology is rising rapidly as a core technology by the bioinformatician, biologist and big-data scientist. KEGG pathway is bioinformatics data for understanding high-level functions and utilities of the biological system. However, KEGG pathway analysis requires a lot of time and effort because KEGG pathways are high volume and very diverse. In this paper, we proposed a network analysis and visualization system that crawl user interest KEGG pathways, construct a pathway network based on a hierarchy structure of pathways and visualize relations and interactions of pathways by clustering and selecting core pathways from the network. Finally, we construct a pathway network collected by starting with an Alzheimer’s disease pathway and show the results on clustering and selecting core pathways from the pathway network.Symmetry2015-07-1673Article10.3390/sym7031275127512882073-89942015-07-16doi: 10.3390/sym7031275Dongmin SeoMin-Ho LeeSeok Yu<![CDATA[Symmetry, Vol. 7, Pages 1261-1274: In Memoriam: Slavik Jablan 1952–2015]]>
http://www.mdpi.com/2073-8994/7/3/1261
After a long and brave battle with a serious illness, our dear friend and colleague Slavik Jablan passed away on 26 February 2015. [...]Symmetry2015-07-1573Obituary10.3390/sym7031261126112742073-89942015-07-15doi: 10.3390/sym7031261Donald CroweGyörgy DarvasDirk HuylebrouckJay KappraffLouis KauffmanSofia LambropoulouJozef PrzytyckiLjiljana RadovićRadmila SazdanovicVera de SpinadelAna ZekovićSymmetry Office<![CDATA[Econometrics, Vol. 3, Pages 532-560: New Graphical Methods and Test Statistics for Testing Composite Normality]]>
http://www.mdpi.com/2225-1146/3/3/532
Several graphical methods for testing univariate composite normality from an i.i.d. sample are presented. They are endowed with correct simultaneous error bounds and yield size-correct tests. As all are based on the empirical CDF, they are also consistent for all alternatives. For one test, called the modified stabilized probability test, or MSP, a highly simplified computational method is derived, which delivers the test statistic and also a highly accurate p-value approximation, essentially instantaneously. The MSP test is demonstrated to have higher power against asymmetric alternatives than the well-known and powerful Jarque-Bera test. A further size-correct test, based on combining two test statistics, is shown to have yet higher power. The methodology employed is fully general and can be applied to any i.i.d. univariate continuous distribution setting.Econometrics2015-07-1533Article10.3390/econometrics30305325325602225-11462015-07-15doi: 10.3390/econometrics3030532Marc Paolella<![CDATA[Econometrics, Vol. 3, Pages 525-531: Efficient Estimation in Heteroscedastic Varying Coefficient Models]]>
http://www.mdpi.com/2225-1146/3/3/525
This paper considers statistical inference for the heteroscedastic varying coefficient model. We propose an efficient estimator for coefficient functions that is more efficient than the conventional local-linear estimator. We establish asymptotic normality for the proposed estimator and conduct some simulation to illustrate the performance of the proposed method.Econometrics2015-07-1533Article10.3390/econometrics30305255255312225-11462015-07-15doi: 10.3390/econometrics3030525Chuanhua WeiLijie Wan<![CDATA[IJGI, Vol. 4, Pages 1201-1224: Prototype of a Web-based Participative Decision Support Platform in Natural Hazards and Risk Management]]>
http://www.mdpi.com/2220-9964/4/3/1201
This paper presents the current state and development of a prototype web-GIS (Geographic Information System) decision support platform intended for application in natural hazards and risk management, mainly for floods and landslides. This web platform uses open-source geospatial software and technologies, particularly the Boundless (formerly OpenGeo) framework and its client side software development kit (SDK). The main purpose of the platform is to assist the experts and stakeholders in the decision-making process for evaluation and selection of different risk management strategies through an interactive participation approach, integrating web-GIS interface with decision support tool based on a compromise programming approach. The access rights and functionality of the platform are varied depending on the roles and responsibilities of stakeholders in managing the risk. The application of the prototype platform is demonstrated based on an example case study site: Malborghetto Valbruna municipality of North-Eastern Italy where flash floods and landslides are frequent with major events having occurred in 2003. The preliminary feedback collected from the stakeholders in the region is discussed to understand the perspectives of stakeholders on the proposed prototype platform.ISPRS International Journal of Geo-Information2015-07-1443Article10.3390/ijgi4031201120112242220-99642015-07-14doi: 10.3390/ijgi4031201Zar AyeMichel JaboyedoffMarc-Henri DerronCees van Westen<![CDATA[Symmetry, Vol. 7, Pages 1211-1260: The Graph, Geometry and Symmetries of the Genetic Code with Hamming Metric]]>
http://www.mdpi.com/2073-8994/7/3/1211
The similarity patterns of the genetic code result from similar codons encoding similar messages. We develop a new mathematical model to analyze these patterns. The physicochemical characteristics of amino acids objectively quantify their differences and similarities; the Hamming metric does the same for the 64 codons of the codon set. (Hamming distances equal the number of different codon positions: AAA and AAC are at 1-distance; codons are maximally at 3-distance.) The CodonPolytope, a 9-dimensional geometric object, is spanned by 64 vertices that represent the codons and the Euclidian distances between these vertices correspond one-to-one with intercodon Hamming distances. The CodonGraph represents the vertices and edges of the polytope; each edge equals a Hamming 1-distance. The mirror reflection symmetry group of the polytope is isomorphic to the largest permutation symmetry group of the codon set that preserves Hamming distances. These groups contain 82,944 symmetries. Many polytope symmetries coincide with the degeneracy and similarity patterns of the genetic code. These code symmetries are strongly related with the face structure of the polytope with smaller faces displaying stronger code symmetries. Splitting the polytope stepwise into smaller faces models an early evolution of the code that generates this hierarchy of code symmetries. The canonical code represents a class of 41,472 codes with equivalent symmetries; a single class among an astronomical number of symmetry classes comprising all possible codes.Symmetry2015-07-1473Article10.3390/sym7031211121112602073-89942015-07-14doi: 10.3390/sym7031211Reijer Lenstra<![CDATA[Systems, Vol. 3, Pages 81-108: Simulation-Based Approach for Studying the Balancing of Local Smart Grids with Electric Vehicle Batteries]]>
http://www.mdpi.com/2079-8954/3/3/81
Modern society is facing great challenges due to pollution and increased carbon dioxide (CO2) emissions. As part of solving these challenges, the use of renewable energy sources and electric vehicles (EVs) is rapidly increasing. However, increased dynamics have triggered problems in balancing energy supply and consumption demand in the power systems. The resulting uncertainty and unpredictability of energy production, consumption, and management of peak loads has caused an increase in costs for energy market actors. Therefore, the means for studying the balancing of local smart grids with EVs is a starting point for this paper. The main contribution is a simulation-based approach which was developed to enable the study of the balancing of local distribution grids with EV batteries in a cost-efficient manner. The simulation-based approach is applied to enable the execution of a distributed system with the simulation of a local distribution grid, including a number of charging stations and EVs. A simulation system has been constructed to support the simulation-based approach. The evaluation has been carried out by executing the scenario related to balancing local distribution grids with EV batteries in a step-by-step manner. The evaluation results indicate that the simulation-based approach is able to facilitate the evaluation of smart grid– and EV-related communication protocols, control algorithms for charging, and functionalities of local distribution grids as part of a complex, critical cyber-physical system. In addition, the simulation system is able to incorporate advanced methods for monitoring, controlling, tracking, and modeling behavior. The simulation model of the local distribution grid can be executed with the smart control of charging and discharging powers of the EVs according to the load situation in the local distribution grid. The resulting simulation system can be applied to the study of balancing local smart grids with EV batteries. Based on the evaluation results, it is estimated that the simulation-based approach can provide an essential, safe, and cost-efficient method for the evaluation of complex, critical cyber-physical systems, such as smart grids.Systems2015-07-1433Article10.3390/systems3030081811082079-89542015-07-14doi: 10.3390/systems3030081Juhani LatvakoskiKari MäkiJussi RonkainenJukka JulkuJani Koivusaari<![CDATA[Algorithms, Vol. 8, Pages 484-513: Multi-Feedback Interference Cancellation Algorithms for OFDM Systems over Doubly-Selective Channels]]>
http://www.mdpi.com/1999-4893/8/3/484
Orthogonal frequency-division multiplexing (OFDM) systems over rapidly time varying channels may suffer from significant inter-carrier interference (ICI), which destroys the orthogonality between subcarriers and degrades the detection performance. Without sufficient ICI suppression, OFDM systems usually experience an error floor. According to the approximate matched filter bound (AMFB), the error floor in a coded OFDM system is not irreducible. In this work, we introduce novel multiple feedback matched filter (MBMF)-based ICI cancellation receivers. Based on the output of a novel MBMF scheme, the approach employs a multiple ICI cancellation strategy with or without signal-to-interference-plus-noise-ratio (SINR) ordering. The developed schemes can significantly improve the performance and remove the error floor with a negligible complexity increase. Given the multiple cancellation approach, we compare the SINR performance of the MBMF outputs with that employing single feedback and show that the SINR performance with multiple cancellation candidates is improved over that with a single one at practical SNR values. Additionally, for time-varying channels, we exploit partial fast Fourier transform (PFFT) by splitting one OFDM symbol into multiple segments; the channel state is separately estimated by least-squares (LS) methods without inserting more pilots. Simulation results demonstrate the superiority of the proposed methods over serial and block equalizers and the robustness to the Doppler effects compared to conventional single-segment method.Algorithms2015-07-1483Article10.3390/a80304844845131999-48932015-07-14doi: 10.3390/a8030484Peng LiMin ChenLi LiJiao Feng<![CDATA[Algorithms, Vol. 8, Pages 466-483: Conditional Random Fields for Pattern Recognition Applied to Structured Data]]>
http://www.mdpi.com/1999-4893/8/3/466
Pattern recognition uses measurements from an input domain, X, to predict their labels from an output domain, Y. Image analysis is one setting where one might want to infer whether a pixel patch contains an object that is “manmade” (such as a building) or “natural” (such as a tree). Suppose the label for a pixel patch is “manmade”; if the label for a nearby pixel patch is then more likely to be “manmade” there is structure in the output domain that can be exploited to improve pattern recognition performance. Modeling P(X) is difficult because features between parts of the model are often correlated. Therefore, conditional random fields (CRFs) model structured data using the conditional distribution P(Y|X = x), without specifying a model for P(X), and are well suited for applications with dependent features. This paper has two parts. First, we overview CRFs and their application to pattern recognition in structured problems. Our primary examples are image analysis applications in which there is dependence among samples (pixel patches) in the output domain. Second, we identify research topics and present numerical examples.Algorithms2015-07-1483Review10.3390/a80304664664831999-48932015-07-14doi: 10.3390/a8030466Tom BurrAlexei Skurikhin<![CDATA[IJGI, Vol. 4, Pages 1184-1200: Housing Abandonment and Demolition: Exploring the Use of Micro-Level and Multi-Year Models]]>
http://www.mdpi.com/2220-9964/4/3/1184
Policies focusing on enforcing property code violations and the improvement of vacant properties are argued to be more efficacious than demolition policies to fight urban blight. This study applies parcel level data to a multi-year hybrid modeling structure. A fine-grained analysis is conducted on the dynamic patterns of abandonment and demolition for a unique period of four years before and after the City of Buffalo’s stepped-up demolition efforts. Results showed that proximity to vacant and abandoned properties, sustained over the years, had the greatest impact on the possibility of a property being abandoned. The second greatest positive impact on property abandonment was small lot front size. Results also showed that neighborhood vacancy density had the greatest negative impact on surrounding housing sales prices over the years. There was no significant impact of demolition on housing sales prices. These findings suggested that the City should aim to have more incentive programs that are tailored to control the number of vacant properties, rather than focusing primarily on demolition-oriented programs.ISPRS International Journal of Geo-Information2015-07-1343Article10.3390/ijgi4031184118412002220-99642015-07-13doi: 10.3390/ijgi4031184Li YinRobert Silverman<![CDATA[Robotics, Vol. 4, Pages 253-283: Leveraging Qualitative Reasoning to Learning Manipulation Tasks]]>
http://www.mdpi.com/2218-6581/4/3/253
Learning and planning are powerful AI methods that exhibit complementary strengths. While planning allows goal-directed actions to be computed when a reliable forward model is known, learning allows such models to be obtained autonomously. In this paper we describe how both methods can be combined using an expressive qualitative knowledge representation. We argue that the crucial step in this integration is to employ a representation based on a well-defined semantics. This article proposes the qualitative spatial logic QSL, a representation that combines qualitative abstraction with linear temporal logic, allowing us to represent relevant information about the learning task, possible actions, and their consequences. Doing so, we empower reasoning processes to enhance learning performance beyond the positive effects of learning in abstract state spaces. Proof-of-concept experiments in two simulation environments show that this approach can help to improve learning-based robotics by quicker convergence and leads to more reliable action planning.Robotics2015-07-1343Article10.3390/robotics40302532532832218-65812015-07-13doi: 10.3390/robotics4030253Diedrich WolterAlexandra Kirsch<![CDATA[Axioms, Vol. 4, Pages 254-267: Lindelöf Σ-Spaces and R-Factorizable Paratopological Groups]]>
http://www.mdpi.com/2075-1680/4/3/254
We prove that if a paratopological group G is a continuous image of an arbitrary product of regular Lindelöf Σ -spaces, then it is R-factorizable and has countable cellularity. If in addition, G is regular, then it is totally w-narrow and satisfies celw(G) ≤ w, and the Hewitt–Nachbin completion of G is again an R-factorizable paratopological group.Axioms2015-07-1043Article10.3390/axioms40302542542672075-16802015-07-10doi: 10.3390/axioms4030254Mikhail Tkachenko<![CDATA[Econometrics, Vol. 3, Pages 494-524: Consistency in Estimation and Model Selection of Dynamic Panel Data Models with Fixed Effects]]>
http://www.mdpi.com/2225-1146/3/3/494
We examine the relationship between consistent parameter estimation and model selection for autoregressive panel data models with fixed effects. We find that the transformation of fixed effects proposed by Lancaster (2002) does not necessarily lead to consistent estimation of common parameters when some true exogenous regressors are excluded. We propose a data dependent way to specify the prior of the autoregressive coefficient and argue for comparing different model specifications before parameter estimation. Model selection properties of Bayes factors and Bayesian information criterion (BIC) are investigated. When model uncertainty is substantial, we recommend the use of Bayesian Model Averaging to obtain point estimators with lower root mean squared errors (RMSE). We also study the implications of different levels of inclusion probabilities by simulations.Econometrics2015-07-1033Article10.3390/econometrics30304944945242225-11462015-07-10doi: 10.3390/econometrics3030494Guangjie Li<![CDATA[Information, Vol. 6, Pages 339-360: Improved Genetic Algorithm Optimization for Forward Vehicle Detection Problems]]>
http://www.mdpi.com/2078-2489/6/3/339
Automated forward vehicle detection is an integral component of many advanced driver-assistance systems. The method based on multi-visual information fusion, with its exclusive advantages, has become one of the important topics in this research field. During the whole detection process, there are two key points that should to be resolved. One is to find the robust features for identification and the other is to apply an efficient algorithm for training the model designed with multi-information. This paper presents an adaptive SVM (Support Vector Machine) model to detect vehicle with range estimation using an on-board camera. Due to the extrinsic factors such as shadows and illumination, we pay more attention to enhancing the system with several robust features extracted from a real driving environment. Then, with the introduction of an improved genetic algorithm, the features are fused efficiently by the proposed SVM model. In order to apply the model in the forward collision warning system, longitudinal distance information is provided simultaneously. The proposed method is successfully implemented on a test car and evaluation experimental results show reliability in terms of both the detection rate and potential effectiveness in a real-driving environment.Information2015-07-1063Article10.3390/info60303393393602078-24892015-07-10doi: 10.3390/info6030339Longhui GangMingheng ZhangXiudong ZhaoShuai Wang<![CDATA[Algorithms, Vol. 8, Pages 459-465: Solving the (n2 − 1)-Puzzle with 8/3 n3 Expected Moves]]>
http://www.mdpi.com/1999-4893/8/3/459
It is shown that the greedy algorithm for the \((n^2-1)\)-puzzle makes \(\tfrac{8}{3}n^3 +O(n^2)\) expected moves. This analysis is verified experimentally on 10,000 random instances each of the \((n^2-1)\)-puzzle for \(4 \leq n \leq 200\).Algorithms2015-07-1083Article10.3390/a80304594594651999-48932015-07-10doi: 10.3390/a8030459Ian Parberry<![CDATA[Algorithms, Vol. 8, Pages 435-458: A Benchmarking Algorithm to Determine Minimum Aggregation Delay for Data Gathering Trees and an Analysis of the Diameter-Aggregation Delay Tradeoff]]>
http://www.mdpi.com/1999-4893/8/3/435
Aggregation delay is the minimum number of time slots required to aggregate data along the edges of a data gathering tree (DG tree) spanning all the nodes in a wireless sensor network (WSN). We propose a benchmarking algorithm to determine the minimum possible aggregation delay for DG trees in a WSN. We assume the availability of a sufficient number of unique CDMA (Code Division Multiple Access) codes for the intermediate nodes to simultaneously aggregate data from their child nodes if the latter are ready with the data. An intermediate node has to still schedule non-overlapping time slots to sequentially aggregate data from its own child nodes (one time slot per child node). We show that the minimum aggregation delay for a DG tree depends on the underlying design choices (bottleneck node-weight based or bottleneck link-weight based) behind its construction. We observe the bottleneck node-weight based DG trees incur a smaller diameter and a larger number of child nodes per intermediate node; whereas, the bottleneck link-weight based DG trees incur a larger diameter and a much lower number of child nodes per intermediate node. As a result, we observe a complex diameter-aggregation delay tradeoff for data gathering trees in WSNs.Algorithms2015-07-1083Article10.3390/a80304354354581999-48932015-07-10doi: 10.3390/a8030435Natarajan Meghanathan<![CDATA[Administrative Sciences, Vol. 5, Pages 125-147: Conflicting Incentives Risk Analysis: A Case Study of the Normative Peer Review Process]]>
http://www.mdpi.com/2076-3387/5/3/125
This paper presents an approach to conduct risk assessments of complex incentive systems, using a case study of the normative Peer Review Process (PRP). This research centers on appliances and adaptations of the Conflicting Incentives Risk Analysis (CIRA). First as an approach to Root Cause Analysis of a known incident, and then for a full assessment of the incentives in the PRP together with possible risk treatments. CIRA uses an alternative notion of risk, where risk modeling is in terms of conflicting incentives between the risk owner and the stakeholders concerning the execution of actions. Compared to traditional risk assessment approaches, CIRA provides an insight into the underlying incentives behind a risk, and not just the technical vulnerability, likelihood and consequence. The main contributions of this work are an approach to obtain insight into incentives as root causes, and an approach to detecting and analyzing risks from incentives in the normative PRP. This paper also discusses risk treatments in terms of incentives to make the PRP more robust, together with a discussion of how to approach risk analysis of incentives.Administrative Sciences2015-07-0953Article10.3390/admsci50301251251472076-33872015-07-09doi: 10.3390/admsci5030125Gaute Wangen<![CDATA[IJGI, Vol. 4, Pages 1166-1183: Does the Visibility of Greenery Increase Perceived Safety in Urban Areas? Evidence from the Place Pulse 1.0 Dataset]]>
http://www.mdpi.com/2220-9964/4/3/1166
Urban green space provides a series of esthetic, environmental and psychological benefits to urban residents. However, the relationship between the visibility of green vegetation and perceived safety is still in debate. This research investigated whether green vegetation could help to increase the perceived safety based on a crowdsourced dataset: the Place Pulse 1.0 dataset. Place Pulse 1.0 dataset, which was generated from a large number of votes by online participants, includes geo-tagged Google Street View images and the corresponding perceived safety score for each image. In this study, we conducted statistical analyses to analyze the relationship between perceived safety and green vegetation characteristics, which were extracted from Google Street View images. Results show that the visibility of green vegetation plays an important role in increasing perceived safety in urban areas. For different land use types, the relationship between vegetation structures and perceived safety varies. In residential, urban public/institutional, commercial and open land areas, the visibility of vegetation higher than 2.5 m has significant positive correlations with perceived safety, but there exists no significant correlation between perceived safety and the percentage of green vegetation in transportation and industrial areas. The visibility of vegetation below 2.5 m has no significant relationship with the perceived safety in almost all land use types, except for multifamily residential land and urban public/institutional land. In general, this study provided insight for the relationship between green vegetation characteristics and the perception of environment, as well as valuable reference data for developing urban greening programs.ISPRS International Journal of Geo-Information2015-07-0943Article10.3390/ijgi4031166116611832220-99642015-07-09doi: 10.3390/ijgi4031166Xiaojiang LiChuanrong ZhangWeidong Li<![CDATA[IJGI, Vol. 4, Pages 1142-1165: Economic Assessment of the Use Value of Geospatial Information]]>
http://www.mdpi.com/2220-9964/4/3/1142
Geospatial data inform decision makers. An economic model that involves application of spatial and temporal scientific, technical, and economic data in decision making is described. The value of information (VOI) contained in geospatial data is the difference between the net benefits (in present value terms) of a decision with and without the information. A range of technologies is used to collect and distribute geospatial data. These technical activities are linked to examples that show how the data can be applied in decision making, which is a cultural activity. The economic model for assessing the VOI in geospatial data for decision making is applied to three examples: (1) a retrospective model about environmental regulation of agrochemicals; (2) a prospective model about the impact and mitigation of earthquakes in urban areas; and (3) a prospective model about developing private–public geospatial information for an ecosystem services market. Each example demonstrates the potential value of geospatial information in a decision with uncertain information.ISPRS International Journal of Geo-Information2015-07-0943Article10.3390/ijgi4031142114211652220-99642015-07-09doi: 10.3390/ijgi4031142Richard BernknopfCarl Shapiro<![CDATA[IJGI, Vol. 4, Pages 1118-1141: Assessing the Impact of Seasonal Population Fluctuation on Regional Flood Risk Management]]>
http://www.mdpi.com/2220-9964/4/3/1118
Human populations are not static or uniformly distributed across space and time. This consideration has a notable impact on natural hazard analyses which seek to determine population exposure and risk. This paper focuses on the coupling of population and environmental models to address the effect of seasonally varying populations on exposure to flood risk. A spatiotemporal population modelling tool, SurfaceBuilder247, has been combined with LISFLOOD-FP flood inundation model outputs for a study area centred on the coastal resort town of St Austell, Cornwall, United Kingdom (UK). Results indicate strong seasonal cycles in populations and their exposure to flood hazard which are not accounted for in traditional population datasets and flood hazard assessments. Therefore, this paper identifies and demonstrates considerable enhancements to the current handling of spatiotemporal population variation within hazard exposure assessment and disaster risk management.ISPRS International Journal of Geo-Information2015-07-0943Article10.3390/ijgi4031118111811412220-99642015-07-09doi: 10.3390/ijgi4031118Alan SmithAndy NewingNiall QuinnDavid MartinSamantha CockingsJeffrey Neal<![CDATA[Axioms, Vol. 4, Pages 235-253: On Elliptic and Hyperbolic Modular Functions and the Corresponding Gudermann Peeta Functions]]>
http://www.mdpi.com/2075-1680/4/3/235
In this article, we move back almost 200 years to Christoph Gudermann, the great expert on elliptic functions, who successfully put the twelve Jacobi functions in a didactic setting. We prove the second hyperbolic series expansions for elliptic functions again, and express generalizations of many of Gudermann’s formulas in Carlson’s modern notation. The transformations between squares of elliptic functions can be expressed as general Möbius transformations, and a conjecture of twelve formulas, extending a Gudermannian formula, is presented. In the second part of the paper, we consider the corresponding formulas for hyperbolic modular functions, and show that these Möbius transformations can be used to prove integral formulas for the inverses of hyperbolic modular functions, which are in fact Schwarz-Christoffel transformations. Finally, we present the simplest formulas for the Gudermann Peeta functions, variations of the Jacobi theta functions. 2010 Mathematics Subject Classification: Primary 33E05; Secondary 33D15.Axioms2015-07-0843Article10.3390/axioms40302352352532075-16802015-07-08doi: 10.3390/axioms4030235Thomas Ernst<![CDATA[Future Internet, Vol. 7, Pages 225-256: EDAS: An Evaluation Prototype for Autonomic Event-Driven Adaptive Security in the Internet of Things]]>
http://www.mdpi.com/1999-5903/7/3/225
In Internet of Things (IoT), the main driving technologies are considered to be tiny sensory objects. These objects cannot host traditional preventive and detective technologies to provide protection against the increasing threat sophistication. Furthermore, these solutions are limited to analyzing particular contextual information, for instance network information or files, and do not provide holistic context for risk analysis and response. Analyzing a part of a situation may lead to false alarms and later to unnecessary and incorrect configurations. To overcome these concerns, we proposed an event-driven adaptive security (EDAS) model for IoT. EDAS aims to observe security events (changes) generated by various things in the monitored IoT environment, investigates any intentional or unintentional risks associated with the events and adapts to it autonomously. It correlates different events in time and space to reduce any false alarms and provides a mechanism to predict attacks before they are realized. Risks are responded to autonomically by utilizing a runtime adaptation ontology. The mitigation action is chosen after assessing essential information, such as the risk faced, user preferences, device capabilities and service requirements. Thus, it selects an optimal mitigation action in a particular adverse situation. The objective of this paper is to investigate EDAS feasibility and its aptitude as a real-world prototype in a remote patient monitoring context. It details how EDAS can be a practical choice for IoT-eHealth in terms of the security, design and implementation features it offers as compared to traditional security controls. We have explained the prototype’s major components and have highlighted the key technical challenges.Future Internet2015-07-0873Article10.3390/fi70302252252561999-59032015-07-08doi: 10.3390/fi7030225Waqas AmanEinar Snekkenes<![CDATA[Mathematics, Vol. 3, Pages 615-625: Reproducing Kernel Hilbert Space vs. Frame Estimates]]>
http://www.mdpi.com/2227-7390/3/3/615
We consider conditions on a given system F of vectors in Hilbert space H, forming a frame, which turn H into a reproducing kernel Hilbert space. It is assumed that the vectors in F are functions on some set Ω . We then identify conditions on these functions which automatically give H the structure of a reproducing kernel Hilbert space of functions on Ω. We further give an explicit formula for the kernel, and for the corresponding isometric isomorphism. Applications are given to Hilbert spaces associated to families of Gaussian processes.Mathematics2015-07-0833Article10.3390/math30306156156252227-73902015-07-08doi: 10.3390/math3030615Palle JorgensenMyung-Sin Song<![CDATA[Algorithms, Vol. 8, Pages 424-434: Multi-Objective Design Optimization of an Over-Constrained Flexure-Based Amplifier]]>
http://www.mdpi.com/1999-4893/8/3/424
The optimizing design for enhancement of the micro performance of manipulator based on analytical models is investigated in this paper. By utilizing the established uncanonical linear homogeneous equations, the quasi-static analytical model of the micro-manipulator is built, and the theoretical calculation results are tested by FEA simulations. To provide a theoretical basis for a micro-manipulator being used in high-precision engineering applications, this paper investigates the modal property based on the analytical model. Based on the finite element method, with multipoint constraint equations, the model is built and the results have a good match with the simulation. The following parametric influences studied show that the influences of other objectives on one objective are complicated. Consequently, the multi-objective optimization by the derived analytical models is carried out to find out the optimal solutions of the manipulator. Besides the inner relationships among these design objectives during the optimization process are discussed.Algorithms2015-07-0883Article10.3390/a80304244244341999-48932015-07-08doi: 10.3390/a8030424Yuan NiZongquan DengJunbao LiXiang WuLong Li<![CDATA[Risks, Vol. 3, Pages 234-249: Options with Extreme Strikes]]>
http://www.mdpi.com/2227-9091/3/3/234
In this short paper, we study the asymptotics for the price of call options for very large strikes and put options for very small strikes. The stock price is assumed to follow the Black–Scholes models. We analyze European, Asian, American, Parisian and perpetual options and conclude that the tail asymptotics for these option types fall into four scenarios.Risks2015-07-0833Article10.3390/risks30302342342492227-90912015-07-08doi: 10.3390/risks3030234Lingjiong Zhu<![CDATA[Computation, Vol. 3, Pages 354-385: Validation of the GPU-Accelerated CFD Solver ELBE for Free Surface Flow Problems in Civil and Environmental Engineering]]>
http://www.mdpi.com/2079-3197/3/3/354
This contribution is dedicated to demonstrating the high potential and manifold applications of state-of-the-art computational fluid dynamics (CFD) tools for free-surface flows in civil and environmental engineering. All simulations were performed with the academic research code ELBE (efficient lattice boltzmann environment, http://www.tuhh.de/elbe). The ELBE code follows the supercomputing-on-the-desktop paradigm and is especially designed for local supercomputing, without tedious accesses to supercomputers. ELBE uses graphics processing units (GPU) to accelerate the computations and can be used in a single GPU-equipped workstation of, e.g., a design engineer. The code has been successfully validated in very different fields, mostly related to naval architecture and mechanical engineering. In this contribution, we give an overview of past and present applications with practical relevance for civil engineers. The presented applications are grouped into three major categories: (i) tsunami simulations, considering wave propagation, wave runup, inundation and debris flows; (ii) dam break simulations; and (iii) numerical wave tanks for the calculation of hydrodynamic loads on fixed and moving bodies. This broad range of applications in combination with accurate numerical results and very competitive times to solution demonstrates that modern CFD tools in general, and the ELBE code in particular, can be a helpful design tool for civil and environmental engineers.Computation2015-07-0733Article10.3390/computation30303543543852079-31972015-07-07doi: 10.3390/computation3030354Christian JanßenDennis MierkeMicha ÜberrückSilke GralherThomas Rung<![CDATA[IJGI, Vol. 4, Pages 1097-1117: Modeling Obstruction and Restoration of Urban Commutation Networks in the Wake of a Devastating Earthquake in Tokyo]]>
http://www.mdpi.com/2220-9964/4/3/1097
In the aftermath of a devastating earthquake, public transportation is presumed paralyzed and thus unavailable; large numbers of people are expected to experience difficulty in commuting. In recent years, implementation of district continuity plans (DCPs) and business continuity plans (BCPs) has become a major concern for local governments and private firms, respectively. In this paper, we propose a pair of simulation models seeking to examine business commutation networks in terms of their possible obstruction and eventual restoration. The first of these model commuting intentions by analyzing individual daily commutes. The second offers a mobility model of commuters’ physical endurance for travel alternatives on foot or by bicycle. Next, we proceed to gauge the number of commuters likely to experience difficulty and adjudge their spatial distribution while taking into account such attributes as gender and employment. Lastly, we attempt to assess rates and patterns in the reduction of commutation constraints based on simulations that assume a restoration of rail infrastructure or its equivalent.ISPRS International Journal of Geo-Information2015-07-0743Article10.3390/ijgi4031097109711172220-99642015-07-07doi: 10.3390/ijgi4031097Toshihiro Osaragi<![CDATA[Algorithms, Vol. 8, Pages 415-423: A Quartically Convergent Jarratt-Type Method for Nonlinear System of Equations]]>
http://www.mdpi.com/1999-4893/8/3/415
In this work, we propose a new fourth-order Jarratt-type method for solving systems of nonlinear equations. The local convergence order of the method is proven analytically. Finally, we validate our results via some numerical experiments including an application to the Chandrashekar integral equations.Algorithms2015-07-0683Article10.3390/a80304154154231999-48932015-07-06doi: 10.3390/a8030415Mohammad GhorbanzadehFazlollah Soleymani<![CDATA[Electronics, Vol. 4, Pages 380-423: Security of Cooperative Intelligent Transport Systems: Standards, Threats Analysis and Cryptographic Countermeasures]]>
http://www.mdpi.com/2079-9292/4/3/380
Due to the growing number of vehicles on the roads worldwide, road traffic accidents are currently recognized as a major public safety problem. In this context, connected vehicles are considered as the key enabling technology to improve road safety and to foster the emergence of next generation cooperative intelligent transport systems (ITS). Through the use of wireless communication technologies, the deployment of ITS will enable vehicles to autonomously communicate with other nearby vehicles and roadside infrastructures and will open the door for a wide range of novel road safety and driver assistive applications. However, connecting wireless-enabled vehicles to external entities can make ITS applications vulnerable to various security threats, thus impacting the safety of drivers. This article reviews the current research challenges and opportunities related to the development of secure and safe ITS applications. It first explores the architecture and main characteristics of ITS systems and surveys the key enabling standards and projects. Then, various ITS security threats are analyzed and classified, along with their corresponding cryptographic countermeasures. Finally, a detailed ITS safety application case study is analyzed and evaluated in light of the European ETSI TC ITS standard. An experimental test-bed is presented, and several elliptic curve digital signature algorithms (ECDSA) are benchmarked for signing and verifying ITS safety messages. To conclude, lessons learned, open research challenges and opportunities are discussed.Electronics2015-07-0643Article10.3390/electronics40303803804232079-92922015-07-06doi: 10.3390/electronics4030380Elyes HamidaHassan NouraWassim Znaidi<![CDATA[IJGI, Vol. 4, Pages 1076-1096: Conception and Implementation of an OGC-Compliant Sensor Observation Service for a Standardized Access to Raster Data]]>
http://www.mdpi.com/2220-9964/4/3/1076
The target of the Open Geospatial Consortium (OGC) is interoperability of geographic information, which means creating opportunities to access geodata in a consistent, standardized way. In the domain of sensor data, the target will be picked up within the OGC Sensor Web Enablement Initiative and especially reached through the Sensor Observation Service (SOS) standard. This one defines a service for a standardized access to time series data and is usually used for in situ sensors (like discharge gauges and climate stations). Although the standard considers raster data, no implementation of the standard for raster data exists presently. In this paper an OGC-compliant Sensor Observation Service for a standardized access to raster data is described. A data model was developed that enables effective storage of the raster data with the corresponding metadata in a database, reading this data in an efficient way, and encoding it with result formats that the SOS-standard provides.ISPRS International Journal of Geo-Information2015-07-0643Article10.3390/ijgi4031076107610962220-99642015-07-06doi: 10.3390/ijgi4031076Juergen SorgRalf Kunkel<![CDATA[JRFM, Vol. 8, Pages 285-310: Inflation and Speculation in a Dynamic Macroeconomic Model]]>
http://www.mdpi.com/1911-8074/8/3/285
We study a monetary version of the Keen model by merging two alternative extensions, namely the addition of a dynamic price level and the introduction of speculation. We recall and study old and new equilibria, together with their local stability analysis. This includes a state of recession associated with a deflationary regime and characterized by falling employment but constant wage shares, with or without an accompanying debt crisis.Journal of Risk and Financial Management2015-07-0683Article10.3390/jrfm80302852853101911-80742015-07-06doi: 10.3390/jrfm8030285Matheus GrasselliAdrien Huu<![CDATA[Computation, Vol. 3, Pages 336-353: In Silico Comparison of the Hemicelluloses Xyloglucan and Glucuronoarabinoxylan in Protecting Cellulose from Degradation]]>
http://www.mdpi.com/2079-3197/3/3/336
We used a previously developed simulation model of a plant cell wall and its enzymatic degradation to compare the abilities of two hemicelluloses, glucuronoarabinoxylan (GAX) and xyloglucan (XG), to protect cellulose microfibrils (CMFs) from attack by cellulose-degrading enzymes. Additionally, we investigated the effect of XG abundance on the degradation rate of CMFs in the presence of the same enzymes. Simulations were run using hypothetical cell-wall compositions in which the numbers and arrangement of CMFs and (1,3;1,4)-β-glucan were kept constant, but the proportions of GAX and XG were altered. Scenarios considered walls with low and equal proportions of either GAX or XG, and also low, medium and high proportions of XG in the absence of GAX. The rate of CMF degradation was much lower in walls with GAX than walls with XG, except for early in the simulation when the reverse held, suggesting that XGs were protecting CMFs by competitive inhibition. Increasing XG content reduced both the degradation rate of CMFs and the percent of XG degraded, indicating that activity of enzymes decreased with XG density despite XG being degradable. Glucose oligosaccharide breakdown products were analysed on the basis of the originating polysaccharide and their degree of polymerisation (DP). The presence of GAX as opposed to equal amounts of XG had some significant effects on the amount and profile of breakdown products from XG and CMFs.Computation2015-07-0633Article10.3390/computation30303363363532079-31972015-07-06doi: 10.3390/computation3030336Indrakumar VetharaniamMartin UpsdellWilliam KellyGraeme AttwoodChristina MoonPhilip Harris<![CDATA[Algorithms, Vol. 8, Pages 407-414: Implementation of a Parallel Algorithm Based on a Spark Cloud Computing Platform]]>
http://www.mdpi.com/1999-4893/8/3/407
Parallel algorithms, such as the ant colony algorithm, take a long time when solving large-scale problems. In this paper, the MAX-MIN Ant System algorithm (MMAS) is parallelized to solve Traveling Salesman Problem (TSP) based on a Spark cloud computing platform. We combine MMAS with Spark MapReduce to execute the path building and the pheromone operation in a distributed computer cluster. To improve the precision of the solution, local optimization strategy 2-opt is adapted in MMAS. The experimental results show that Spark has a very great accelerating effect on the ant colony algorithm when the city scale of TSP or the number of ants is relatively large.Algorithms2015-07-0383Article10.3390/a80304074074141999-48932015-07-03doi: 10.3390/a8030407Longhui WangYong WangYudong Xie<![CDATA[Mathematics, Vol. 3, Pages 604-614: Topological Integer Additive Set-Sequential Graphs]]>
http://www.mdpi.com/2227-7390/3/3/604
Let \(\mathbb{N}_0\) denote the set of all non-negative integers and \(X\) be any non-empty subset of \(\mathbb{N}_0\). Denote the power set of \(X\) by \(\mathcal{P}(X)\). An integer additive set-labeling (IASL) of a graph \(G\) is an injective function \(f : V (G) \to P(X)\) such that the image of the induced function \(f^+: E(G) \to \mathcal{P}(\mathbb{N}_0)\), defined by \(f^+(uv)=f(u)+f(v)\), is contained in \(\mathcal{P}(X)\), where \(f(u) + f(v)\) is the sumset of \(f(u)\) and \(f(v)\). If the associated set-valued edge function \(f^+\) is also injective, then such an IASL is called an integer additive set-indexer (IASI). An IASL \(f\) is said to be a topological IASL (TIASL) if \(f(V(G))\cup \{\emptyset\}\) is a topology of the ground set \(X\). An IASL is said to be an integer additive set-sequential labeling (IASSL) if \(f(V(G))\cup f^+(E(G))= \mathcal{P}(X)-\{\emptyset\}\). An IASL of a given graph \(G\) is said to be a topological integer additive set-sequential labeling of \(G\), if it is a topological integer additive set-labeling as well as an integer additive set-sequential labeling of \(G\). In this paper, we study the conditions required for a graph \(G\) to admit this type of IASL and propose some important characteristics of the graphs which admit this type of IASLs.Mathematics2015-07-0333Article10.3390/math30306046046142227-73902015-07-03doi: 10.3390/math3030604Sudev NaduvathGermina AugustineChithra Sudev<![CDATA[Technologies, Vol. 3, Pages 162-181: On the Use of Local Search in the Evolution of Neural Networks for the Diagnosis of Breast Cancer]]>
http://www.mdpi.com/2227-7080/3/3/162
With the advancement in the field of Artificial Intelligence, there have been considerable efforts to develop technologies for pattern recognition related to medical diagnosis. Artificial Neural Networks (ANNs), a significant piece of Artificial Intelligence forms the base for most of the marvels in the former field. However, ANNs face the problem of premature convergence at a local minimum and inability to set hyper-parameters (like the number of neurons, learning rate, etc.) while using Back Propagation Algorithm (BPA). In this paper, we have used the Genetic Algorithm (GA) for the evolution of the ANN, which overcomes the limitations of the BPA. Since GA alone cannot fit for a high-dimensional, complex and multi-modal optimization landscape of the ANN, BPA is used as a local search algorithm to aid the evolution. The contributions of GA and BPA in the resultant approach are adjudged to determine the magnitude of local search necessary for optimization, striking a clear balance between exploration and exploitation in the evolution. The algorithm was applied to deal with the problem of Breast Cancer diagnosis. Results showed that under optimal settings, hybrid algorithm performs better than BPA or GA alone.Technologies2015-07-0333Article10.3390/technologies30301621621812227-70802015-07-03doi: 10.3390/technologies3030162Agam GuptaShiva BhallaShishir DwivediNitin VermaRahul Kala<![CDATA[Axioms, Vol. 4, Pages 213-234: Scientific Endeavors of A.M. Mathai: An Appraisal on the Occasion of his Eightieth Birthday, 28 April 2015]]>
http://www.mdpi.com/2075-1680/4/3/213
A.M. Mathai is Emeritus Professor of Mathematics and Statistics at McGill University, Canada. He is currently the Director of the Centre for Mathematical and Statistical Sciences India. His research contributions cover a wide spectrum of topics in mathematics, statistics, physics, astronomy, and biology. He is a Fellow of the Institute of Mathematical Statistics, National Academy of Sciences of India, and a member of the International Statistical Institute. He is a founder of the Canadian Journal of Statistics and the Statistical Society of Canada. He was instrumental in the implementation of the United Nations Basic Space Science Initiative (1991–2012). This paper highlights research results of A.M. Mathai in the period of time from 1962 to 2015. He published over 300 research papers and over 25 books.Axioms2015-07-0343Editorial10.3390/axioms40302132132342075-16802015-07-03doi: 10.3390/axioms4030213Hans HauboldArak Mathai<![CDATA[Information, Vol. 6, Pages 314-338: Mind, Matter, Information and Quantum Interpretations]]>
http://www.mdpi.com/2078-2489/6/3/314
In this paper I give a new information-theoretic analysis of the formalisms and interpretations of quantum mechanics (QM) in general, and of two mainstream interpretations of quantum mechanics in particular: The Copenhagen interpretation and David Bohm’s interpretation of quantum mechanics. Adopting Juan G. Roederer’s reading of the notion of pragmatic information, I argue that pragmatic information is not applicable to the Copenhagen interpretation since the interpretation is primarily concerned with epistemology rather than ontology. However it perfectly fits Bohm’s ontological interpretation of quantum mechanics in the realms of biotic and artificial systems. Viewing Bohm’s interpretation of QM in the context of pragmatic information imposes serious limitations to the qualitative aspect of such an interpretation, making his extension of the notion active information to every level of reality illegitimate. Such limitations lead to the idea that, contrary to Bohm’s claim, mind is not a more subtle aspect of reality via the quantum potential as active information, but the quantum potential as it affects particles in the double-slit experiment represents the non-algorithmic aspect of the mind as a genuine information processing system. This will provide an information-based ground, firstly, for refreshing our views on quantum interpretations and secondly, for a novel qualitative theory of the relationship of mind and matter in which mind-like properties are exclusive attributes of living systems. To this end, I will also take an information-theoretic approach to the notion of intentionality as interpreted by John Searle.Information2015-07-0263Article10.3390/info60303143143382078-24892015-07-02doi: 10.3390/info6030314Reza Maleeh<![CDATA[Computers, Vol. 4, Pages 176-214: A Cloud Based Mobile Dispatching System with Built-in Social CRM Component: Design and Implementation]]>
http://www.mdpi.com/2073-431X/4/3/176
Mobile dispatching applications have become popular for at least two major reasons. The first reason is a more mobile-centric usage pattern, where users relate to apps for fulfilling different needs that they have. In this respect, a vehicle dispatching application for mobile phones is perceived as a modern way of booking a vehicle. The second reason has to do with the advantages that this method has over traditional dispatching systems, such as being able to see the vehicle approaching on a map, being able to rate a driver and the most importantly spurring customer retention. The taxi dispatching business, one of the classes of dispatching businesses, tends to be a medium to lower class fidelity service, where users mostly consider the closest taxi as opposed to quality, which is regarded as being at a relatively consistent level. We propose a new approach for the taxi ordering application , a mobile dispatching system, which allows for a more engaged user base and offers fidelity rewards that are used to enhance the customer retention level based on a built in social customer relationship management (CRM) component. With this approach, we argue that in a business world which is shifting from a consumer-centric marketing to a human-centric model, this apps will allows taxi businesses to better interact with their clients in a more direct and responsible manner. Also this distributed system helps taxi drivers, which can receive orders directly from their clients and will be able to benefit from offering quality services as they can get higher ratings.Computers2015-07-0243Project Report10.3390/computers40301761762142073-431X2015-07-02doi: 10.3390/computers4030176Cosmina IvanRazvan Popa<![CDATA[IJGI, Vol. 4, Pages 1055-1075: Modeling a 3D City Model and Its Levels of Detail as a True 4D Model]]>
http://www.mdpi.com/2220-9964/4/3/1055
The various levels of detail (LODs) of a 3D city model are often stored independently, without links between the representations of the same object, causing inconsistencies, as well as update and maintenance problems. One solution to this problem is to model the LOD as an extra geometric dimension perpendicular to the three spatial ones, resulting in a true 4D model in which a single 4D object (a polychoron) represents a 3D polyhedral object (e.g., a building) at all of its LODs and a multiple-LOD 3D city model is modeled as a 4D cell complex. While such an approach has been discussed before at a conceptual level, our objective in this paper is to describe how it can be realized by appropriately linking existing 3D models of the same object at different LODs. We first present our general methodology to construct such a 4D model, which consists of three steps: (1) finding corresponding 0D–3D cells; (2) creating 1D–4D cells connecting them; and (3) constructing the 4D model. Because of the complex relationships between the objects in different LODs, the creation of the connecting cells can become difficult. We therefore describe four different alternatives to do this, and we discuss the advantages and disadvantages of each in terms of their feasibility in practice and the properties that the resulting 4D model has. We show how the different linking schemes result in objects with different characteristics in several use cases. We also show how our linking method works in practice by implementing the linking of matching cells to construct a 4D model.ISPRS International Journal of Geo-Information2015-07-0243Article10.3390/ijgi4031055105510752220-99642015-07-02doi: 10.3390/ijgi4031055Ken OhoriHugo LedouxFilip BiljeckiJantien Stoter<![CDATA[Symmetry, Vol. 7, Pages 1176-1210: Real Time MODBUS Transmissions and Cryptography Security Designs and Enhancements of Protocol Sensitive Information]]>
http://www.mdpi.com/2073-8994/7/3/1176
Information technology (IT) security has become a major concern due to the growing demand for information and massive development of client/server applications for various types of applications running on modern IT infrastructure. How has security been taken into account and which paradigms are necessary to minimize security issues while increasing efficiency, reducing the influence on transmissions, ensuring protocol independency and achieving substantial performance? We have found cryptography to be an absolute security mechanism for client/server architectures, and in this study, a new security design was developed with the MODBUS protocol, which is considered to offer phenomenal performance for future development and enhancement of real IT infrastructure. This study is also considered to be a complete development because security is tested in almost all ways of MODBUS communication. The computed measurements are evaluated to validate the overall development, and the results indicate a substantial improvement in security that is differentiated from conventional methods.Symmetry2015-07-0273Article10.3390/sym7031176117612102073-89942015-07-02doi: 10.3390/sym7031176Aamir ShahzadMalrey LeeYoung-Keun LeeSuntae KimNaixue XiongJae-Young ChoiYounghwa Cho<![CDATA[Symmetry, Vol. 7, Pages 1164-1175: Hierarchical Clustering Using One-Class Support Vector Machines]]>
http://www.mdpi.com/2073-8994/7/3/1164
This paper presents a novel hierarchical clustering method using support vector machines. A common approach for hierarchical clustering is to use distance for the task. However, different choices for computing inter-cluster distances often lead to fairly distinct clustering outcomes, causing interpretation difficulties in practice. In this paper, we propose to use a one-class support vector machine (OC-SVM) to directly find high-density regions of data. Our algorithm generates nested set estimates using the OC-SVM and exploits the hierarchical structure of the estimated sets. We demonstrate the proposed algorithm on synthetic datasets. The cluster hierarchy is visualized with dendrograms and spanning trees.Symmetry2015-07-0173Article10.3390/sym7031164116411752073-89942015-07-01doi: 10.3390/sym7031164Gyemin Lee<![CDATA[JSAN, Vol. 4, Pages 154-159: Radio/Antenna Mounting System for Wireless Networking under Row-Crop Agriculture Conditions]]>
http://www.mdpi.com/2224-2708/4/3/154
Interest in and deployment of wireless monitoring systems is increasing in many diverse environments, including row-crop agricultural fields. While many studies have been undertaken to evaluate various aspects of wireless monitoring and networking, such as electronic hardware components, data-collection procedures, power management, and communication protocols, little information related to physical deployment issues has been reported. To achieve acceptable wireless transmission capability, the radio/antenna must be positioned properly relative to the ground surface or crop canopy to minimize degradation of the radio signal, usually requiring the mounting of the radio/antenna above the canopy. This results in the presence of obstacles to normal agricultural equipment traffic and production operations and potential damage to the wireless monitoring system. A simple and rugged radio/antenna mounting system was designed which could be subjected to encounters with agricultural equipment without suffering physical damage. The mounting system was deployed and tested, and operated successfully following repeated encounters with various agricultural machines and implements. The radio/antenna mount is simple and inexpensive to fabricate using locally available components.Journal of Sensor and Actuator Networks2015-07-0143Communication10.3390/jsan40301541541592224-27082015-07-01doi: 10.3390/jsan4030154Daniel Fisher<![CDATA[Systems, Vol. 3, Pages 62-80: Dealing with Multi-Level Governance and Wicked Problems in Urban Transportation Systems: The Case of Palermo Municipality]]>
http://www.mdpi.com/2079-8954/3/3/62
Italian New Public Management (NPM) has been mainly characterized by a political orientation toward power decentralization to local governments and privatization of public companies. Nowadays, local utilities in Italy are often run by joint stock companies controlled by public agencies such as Regional and Municipal Administrations. Due to this transformation, these companies must comply with a set of diverse expectations coming from a wide range of stakeholders, related to their financial, competitive and social performance. Such fragmented governance increases the presence of “wicked” problems in the decision-making sphere of these entities. Given this multi-level governance structure, how do these agents influence public services performance? In recent years, coordination and inter-institutional joint action have been identified as possible approaches for dealing with governance fragmentation and wicked problems deriving from it. How can we adapt a performance management perspective in order to help us reform the system and so have a better collaboration between the stakeholders involved? In order to address and discuss these research questions, a case study will be developed. The case concerns AMAT, the local utility providing the public transportation service in the Municipality of Palermo (Italy). The result of this study is a dynamic model including a set of performance indicators that help us in understanding the impact of the governing structure on the system’s performance.Systems2015-06-3033Article10.3390/systems303006262802079-89542015-06-30doi: 10.3390/systems3030062Guido NotoCarmine Bianchi<![CDATA[Econometrics, Vol. 3, Pages 466-493: A New Approach to Model Verification, Falsification and Selection]]>
http://www.mdpi.com/2225-1146/3/3/466
This paper shows that a qualitative analysis, i.e., an assessment of the consistency of a hypothesized sign pattern for structural arrays with the sign pattern of the estimated reduced form, can always provide decisive insight into a model’s validity both in general and compared to other models. Qualitative analysis can show that it is impossible for some models to have generated the data used to estimate the reduced form, even though standard specification tests might show the model to be adequate. A partially specified structural hypothesis can be falsified by estimating as few as one reduced form equation. Zero restrictions in the structure can themselves be falsified. It is further shown how the information content of the hypothesized structural sign patterns can be measured using a commonly applied concept of statistical entropy. The lower the hypothesized structural sign pattern’s entropy, the more a priori information it proposes about the sign pattern of the estimated reduced form. As an hypothesized structural sign pattern has a lower entropy, it is more subject to type 1 error and less subject to type 2 error. Three cases illustrate the approach taken here.Econometrics2015-06-2933Article10.3390/econometrics30304664664932225-11462015-06-29doi: 10.3390/econometrics3030466Andrew BuckGeorge Lady<![CDATA[Algorithms, Vol. 8, Pages 395-406: Algorithms for Computerized Fetal Heart Rate Diagnosis with Direct Reporting]]>
http://www.mdpi.com/1999-4893/8/3/395
Aims: Since pattern classification of fetal heart rate (FHR) was subjective and enlarged interobserver difference, objective FHR analysis was achieved with computerized FHR diagnosis. Methods: The computer algorithm was composed of an experts’ knowledge system, including FHR analysis and FHR score calculation, and also of an objective artificial neural network system with software. In addition, a FHR frequency spectrum was studied to detect ominous sinusoidal FHR and the loss of baseline variability related to fetal brain damage. The algorithms were installed in a central-computerized automatic FHR monitoring system, which gave the diagnosis rapidly and directly to the attending doctor. Results: Clinically perinatal mortality decreased significantly and no cerebral palsy developed after introduction of the centralized system. Conclusion: The automatic multichannel FHR monitoring system improved the monitoring, increased the objectivity of FHR diagnosis and promoted clinical results.Algorithms2015-06-2983Review10.3390/a80303953954061999-48932015-06-29doi: 10.3390/a8030395Kazuo MaedaYasuaki NoguchiMasaji UtsuTakashi Nagassawa<![CDATA[Mathematics, Vol. 3, Pages 563-603: Singular Bilinear Integrals in Quantum Physics]]>
http://www.mdpi.com/2227-7390/3/3/563
Bilinear integrals of operator-valued functions with respect to spectral measures and integrals of scalar functions with respect to the product of two spectral measures arise in many problems in scattering theory and spectral analysis. Unfortunately, the theory of bilinear integration with respect to a vector measure originating from the work of Bartle cannot be applied due to the singular variational properties of spectral measures. In this work, it is shown how ``decoupled'' bilinear integration may be used to find solutions \(X\) of operator equations \(AX-XB=Y\) with respect to the spectral measure of \(A\) and to apply such representations to the spectral decomposition of block operator matrices. A new proof is given of Peller's characterisation of the space \(L^1((P\otimes Q)_{\mathcal L(\mathcal H)})\) of double operator integrable functions for spectral measures \(P\), \(Q\) acting in a Hilbert space \(\mathcal H\) and applied to the representation of the trace of \(\int_{\Lambda\times\Lambda}\varphi\,d(PTP)\) for a trace class operator \(T\). The method of double operator integrals due to Birman and Solomyak is used to obtain an elementary proof of the existence of Krein's spectral shift function.Mathematics2015-06-2933Article10.3390/math30305635636032227-73902015-06-29doi: 10.3390/math3030563Brian Jefferies<![CDATA[Future Internet, Vol. 7, Pages 214-224: Tracking Positioning Algorithm for Direction of Arrival Based on Direction Lock Loop]]>
http://www.mdpi.com/1999-5903/7/3/214
In order to solve the problem of poor real-time performance, low accuracy and high computational complexity in the traditional process of locating and tracking of Direction of Arrival (DOA) of moving targets, this paper proposes a DOA algorithm based on the Direction Lock Loop (DILL) which adopts Lock Loop structure to realize the estimation and location of DOA and can adjust the direction automatically along with the changes of a signal’s angular variation to track the position of the signal. Meanwhile, to reduce the influence of nonlinearity and noise on its performance, the UKF filter is designed for eliminating interference of the estimated target signal to improve accuracy of the signal tracking and stability of the system. Simulation results prove that the algorithm can not only get a high resolution DOA estimate signal, but can also locate and track multiple mobile targets effectively with enhanced accuracy, efficiency and stability.Future Internet2015-06-2673Article10.3390/fi70302142142241999-59032015-06-26doi: 10.3390/fi7030214Xiu-Zhi ChengDa-Rong ZhuShen ZhangPing He<![CDATA[IJFS, Vol. 3, Pages 177-193: Net Interoffice Accounts of Global Banks: The Role of Domestic Funding]]>
http://www.mdpi.com/2227-7072/3/3/177
Existing literature has identified domestic restrictive monetary policy and deteriorating funding conditions as the predominant factors explaining the increase in net interoffice accounts of global banks, that is, the net liabilities of parent offices due to their related foreign offices. The purpose of this research is twofold. Firstly, it quantifies the responsiveness of net interoffice accounts to variations in different types of domestic funding. Secondly, the paper assesses whether the relationship between net interoffice accounts and domestic policy-steered rates depends on cross-sectional differences in the funding structure of global banks. Using US banks’ balance sheets data collected by the Federal Financial Institutions Examination Council, the results highlight the importance of domestic repo borrowings in explaining net interoffice accounts, especially for larger banks during the crisis. On the other hand, a negative relationship between policy rates and net interoffice accounts is observed only for those global banks with a relatively higher share of repo borrowings.International Journal of Financial Studies2015-06-2633Article10.3390/ijfs30301771771932227-70722015-06-26doi: 10.3390/ijfs3030177Carmela D'Avino<![CDATA[IJGI, Vol. 4, Pages 1033-1054: Hybrid 3D Rendering of Large Map Data for Crisis Management]]>
http://www.mdpi.com/2220-9964/4/3/1033
In this paper we investigate the use of games technologies for the research and the development of 3D representations of real environments captured from GIS information and open source map data. Challenges involved in this area concern the large data-sets to be dealt with. Some existing map data include errors and are not complete, which makes the generation of realistic and accurate 3D environments problematic. The domain of application of our work is crisis management which requires very accurate GIS or map information. We believe the use of creating a 3D virtual environment using real map data whilst correcting and completing the missing data, improves the quality and performance of crisis management decision support system to provide a more natural and intuitive interface for crisis managers. Consequently, we present a case study into issues related to combining multiple large datasets to create an accurate representation of a novel, multi-layered, hybrid real-world maps. The hybrid map generation combines LiDAR, Ordnance Survey, and OpenStreetMap data to generate 3D cities spanning 1 km2. Evaluation of initial visualised scenes is presented. Initial tests consist of a 1 km2 landscape map containing up to 16 million vertices’ and run at an optimal 51.66 frames per-second.ISPRS International Journal of Geo-Information2015-06-2643Article10.3390/ijgi4031033103310542220-99642015-06-26doi: 10.3390/ijgi4031033David TullyAbdennour RhalibiChristopher CarterSud Sudirman<![CDATA[Algorithms, Vol. 8, Pages 380-394: Improving CLOPE’s Profit Value and Stability with an Optimized Agglomerative Approach]]>
http://www.mdpi.com/1999-4893/8/3/380
CLOPE (Clustering with sLOPE) is a simple and fast histogram-based clustering algorithm for categorical data. However, given the same data set with the same input parameter, the clustering results by this algorithm would possibly be different if the transactions are input in a different sequence. In this paper, a hierarchical clustering framework is proposed as an extension of CLOPE to generate stable and satisfactory clustering results based on an optimized agglomerative merge process. The new clustering profit is defined as the merge criteria and the cluster graph structure is proposed to optimize the merge iteration process. The experiments conducted on two datasets both demonstrate that the agglomerative approach achieves stable clustering results with a better profit value, but costs much more time due to the worse complexity.Algorithms2015-06-2683Article10.3390/a80303803803941999-48932015-06-26doi: 10.3390/a8030380Yefeng LiJiajin LeMei Wang<![CDATA[Symmetry, Vol. 7, Pages 1151-1163: Multiple Minimum Support-Based Rare Graph Pattern Mining Considering Symmetry Feature-Based Growth Technique and the Differing Importance of Graph Elements]]>
http://www.mdpi.com/2073-8994/7/3/1151
Frequent graph pattern mining is one of the most interesting areas in data mining, and many researchers have developed a variety of approaches by suggesting efficient, useful mining techniques by integration of fundamental graph mining with other advanced mining works. However, previous graph mining approaches have faced fatal problems that cannot consider important characteristics in the real world because they cannot process both (1) different element importance and (2) multiple minimum support thresholds suitable for each graph element. In other words, graph elements in the real world have not only frequency factors but also their own importance; in addition, various elements composing graphs may require different thresholds according to their characteristics. However, traditional ones do not consider such features. To overcome these issues, we propose a new frequent graph pattern mining method, which can deal with both different element importance and multiple minimum support thresholds. Through the devised algorithm, we can obtain more meaningful graph pattern results with higher importance. We also demonstrate that the proposed algorithm has more outstanding performance compared to previous state-of-the-art approaches in terms of graph pattern generation, runtime, and memory usage.Symmetry2015-06-2673Article10.3390/sym7031151115111632073-89942015-06-26doi: 10.3390/sym7031151Gangin LeeUnil YunHeungmo RyangDonggyu Kim<![CDATA[Information, Vol. 6, Pages 300-313: ANFIS Based Time Series Prediction Method of Bank Cash Flow Optimized by Adaptive Population Activity PSO Algorithm]]>
http://www.mdpi.com/2078-2489/6/3/300
In order to improve the accuracy and real-time of all kinds of information in the cash business, and solve the problem which accuracy and stability is not high of the data linkage between cash inventory forecasting and cash management information in the commercial bank, a hybrid learning algorithm is proposed based on adaptive population activity particle swarm optimization (APAPSO) algorithm combined with the least squares method (LMS) to optimize the adaptive network-based fuzzy inference system (ANFIS) model parameters. Through the introduction of metric function of population diversity to ensure the diversity of population and adaptive changes in inertia weight and learning factors, the optimization ability of the particle swarm optimization (PSO) algorithm is improved, which avoids the premature convergence problem of the PSO algorithm. The simulation comparison experiments are carried out with BP-LMS algorithm and standard PSO-LMS by adopting real commercial banks’ cash flow data to verify the effectiveness of the proposed time series prediction of bank cash flow based on improved PSO-ANFIS optimization method. Simulation results show that the optimization speed is faster and the prediction accuracy is higher.Information2015-06-2463Article10.3390/info60303003003132078-24892015-06-24doi: 10.3390/info6030300Jie-Sheng WangChen-Xu Ning<![CDATA[Information, Vol. 6, Pages 287-299: Robust Sparse Representation for Incomplete and Noisy Data]]>
http://www.mdpi.com/2078-2489/6/3/287
Owing to the robustness of large sparse corruptions and the discrimination of class labels, sparse signal representation has been one of the most advanced techniques in the fields of pattern classification, computer vision, machine learning and so on. This paper investigates the problem of robust face classification when a test sample has missing values. Firstly, we propose a classification method based on the incomplete sparse representation. This representation is boiled down to an l1 minimization problem and an alternating direction method of multipliers is employed to solve it. Then, we provide a convergent analysis and a model extension on incomplete sparse representation. Finally, we conduct experiments on two real-world face datasets and compare the proposed method with the nearest neighbor classifier and the sparse representation-based classification. The experimental results demonstrate that the proposed method has the superiority in classification accuracy, completion of the missing entries and recovery of noise.Information2015-06-2463Article10.3390/info60302872872992078-24892015-06-24doi: 10.3390/info6030287Jiarong ShiXiuyun ZhengWei Yang<![CDATA[Algorithms, Vol. 8, Pages 366-379: Identification of Dual-Rate Sampled Hammerstein Systems with a Piecewise-Linear Nonlinearity Using the Key Variable Separation Technique]]>
http://www.mdpi.com/1999-4893/8/3/366
The identification difficulties for a dual-rate Hammerstein system lie in two aspects. First, the identification model of the system contains the products of the parameters of the nonlinear block and the linear block, and a standard least squares method cannot be directly applied to the model; second, the traditional single-rate discrete-time Hammerstein model cannot be used as the identification model for the dual-rate sampled system. In order to solve these problems, by combining the polynomial transformation technique with the key variable separation technique, this paper converts the Hammerstein system into a dual-rate linear regression model about all parameters (linear-in-parameter model) and proposes a recursive least squares algorithm to estimate the parameters of the dual-rate system. The simulation results verify the effectiveness of the proposed algorithm.Algorithms2015-06-2483Article10.3390/a80303663663791999-48932015-06-24doi: 10.3390/a8030366Ying-Ying WangXiang-Dong WangDong-Qing Wang<![CDATA[Informatics, Vol. 2, Pages 4-19: Human–Information Interaction with Complex Information for Decision-Making]]>
http://www.mdpi.com/2227-9709/2/2/4
Human–information interaction (HII) for simple information and for complex information is different because people’s goals and information needs differ between the two cases. With complex information, comprehension comes from understanding the relationships and interactions within the information and factors outside of a design team’s control. Yet, a design team must consider all these within an HII design in order to maximize the communication potential. This paper considers how simple and complex information requires different design strategies and how those strategies differ.Informatics2015-06-2322Article10.3390/informatics20200044192227-97092015-06-23doi: 10.3390/informatics2020004Michael Albers<![CDATA[Axioms, Vol. 4, Pages 194-212: On T-Characterized Subgroups of Compact Abelian Groups]]>
http://www.mdpi.com/2075-1680/4/2/194
A sequence \(\{ u_n \}_{n\in \omega}\) in abstract additively-written Abelian group \(G\) is called a \(T\)-sequence if there is a Hausdorff group topology on \(G\) relative to which \(\lim_n u_n =0\). We say that a subgroup \(H\) of an infinite compact Abelian group \(X\) is \(T\)-characterized if there is a \(T\)-sequence \(\mathbf{u} =\{ u_n \}\) in the dual group of \(X\), such that \(H=\{ x\in X: \; (u_n, x)\to 1 \}\). We show that a closed subgroup \(H\) of \(X\) is \(T\)-characterized if and only if \(H\) is a \(G_\delta\)-subgroup of \(X\) and the annihilator of \(H\) admits a Hausdorff minimally almost periodic group topology. All closed subgroups of an infinite compact Abelian group \(X\) are \(T\)-characterized if and only if \(X\) is metrizable and connected. We prove that every compact Abelian group \(X\) of infinite exponent has a \(T\)-characterized subgroup, which is not an \(F_{\sigma}\)-subgroup of \(X\), that gives a negative answer to Problem 3.3 in Dikranjan and Gabriyelyan (Topol. Appl. 2013, 160, 2427–2442).Axioms2015-06-1942Article10.3390/axioms40201941942122075-16802015-06-19doi: 10.3390/axioms4020194Saak Gabriyelyan